Halbe haploide Chromosomenzahl im Hoden vonMyrmica sulcinodis Nyl. (Formicidae)

Summary In the testes ofMyrmica sulcinodis there are not only haploid and some diploid cells to be found, as in the testes ofM. ruginodis, M. sabulsti andM. rubida, but a large mass of cells that have only half the haploid chromosome number. The diploid chromosome number ofM. sulcinodis is 56, those of six otherMyrmica species are between 42 and 48.     

Presenza di enteramina o di una sostanza enteraminosimile negli estratti gastrointestinali e splenici dei pesci e negli estratti gastroenterici delle Ascidie

Summary It was possible to demonstrate, by means of chemical and biological reactions, the presence of enteramine or of an enteramine-like substance in gastro-intestinal extracts of twoAscidi, Tethium plicatum andCiona intestinalis.The same substance was also found in gastric and still more in intestinal extracts ofSelacia, but seems not to be present in the spleen ofSelacia nor in the alimentary canal ofTeleostea.     

Sur l'activité tuberculostatique des N-arylglycinespara-substituées

Summary Several compounds belonging to the group ofpara-substituted N-arylglycines have been found to exhibit pronounced tuberculostatic activityin vitro, but are too toxic for practical application. The relationship between chemical structure and activity is similar to that observed in the group of thiocarbanilides.     

Chemical and tactile communication between the root aphid parasitoidParalipsis enervis and trophobiotic ants: consequences for parasitoid survival

Females of the aphid parasitoidParalipsis enervis received liquid food by regurgitation (trophallaxis) from workers of the ant speciesLasius niger, but were not fed by workers ofMyrmica laevinodis andTetramorium caespitum. WhileP. enervis was not treated aggressively by workers of any of these species,Lasius flavus workers killed the parasitoid. This different ant behaviour resulted in a different parasitoid longevity. WhileP. enervis survived for only 10 min in the presence ofL. flavus (due to ant aggression) or for approximately one day in the presence ofT. caespitum andM. laevinodis (due to lack of trophallaxis), survival increased significantly to more than five days in the presence ofL. niger, which provided food regularly to the parasitoids. Our study suggests thatP. enervis mimics behavioural signals ofL. niger, as well as odor cues of its host aphidAnoecia corni, to avoid aggression byL. niger.     

Untersuchungen über Ultrastruktur und Aminosäurenzusammensetzung der Eischalen vonNatrix natrix

Summary The ultrastructures of eggshells ofNatrix natrix and the membrana testacea ofGallus gallus dom. are very similar, with the exception of cavity systems which only exist in eggshells of snakes (ringsnake) but not in the membrana testacea of birds. In the sheath of the fibres ofNatrix natrix, a positive ruthenium redreaction indicates the presence of mucopolysacharides, or proteoglycans. The eggshells ofNatrix natrix contain a high proportion of proline, but also of cystine, histidine and arginine. The high proline content is discussed with regard to the properties of poly-l-proline. Presumably proteins similar to collagen exist in eggshells ofNatrix natrix.     

A new alarm pheromone (2-decen-1-yl-acetate) isolated from the stings ofApis dorsata andApis florea (Hymenoptera: Apidae)

Summary From sting extracts ofApis dorsata andA. florea, a substance was isolated which is active in alarm behaviour of both of these species but not ofA. mellifera andA. cerana. The active substance was identified as 2-decen-1-yl-acetate.     

Harvesting large amounts of Drosophila embryos at precisely defined stages

Summary A simple method is described which makes it possible to eliminate the retained eggs ofDrosophila melanogaster and to harvest a large amount of embryos at a defined stage of development. It is based upon carbon dioxide anesthesia, which brings about the expulsion of eggs remaining in the uterus.     

Osservazioni preliminari,chimiche e farmacologiche,sulla murexina

Summary (1) Murexine, a new choline derivative found in the hypobranchial body ofMurex trunculus, Murex brandaris, andTritonalia erinacea, was isolated as picrate, picrolonate, styphnate, flavianate, and reineckate. Some preliminary characteristics of these salts are given.(2) The murexine content of the median zone of the hypobranchial body ofMurex trunculus is extremely high: murexine picrate equivalents of 45–70 mg per g fresh tissue are commonly observed.(3) Murexine manifests intense nicotinic and curariform actions, but is practically wanting in any muscarinic activity.The central nervous system is strongly affected by the substance: at first stimulation seems to prevail, but later on, with larger doses, a deep depression regularly develops.In decapitated cats and dogs murexine causes a significant rise in blood pressure, which is due, at least partially, to a liberation of epinephrine from the adrenal medulla and from the adrenergic nerve terminals.On the enucleated eye of frogs andOctopoda the substance acts to cause mydriasis and expansion of the iris chromatophora.

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V. Erspamer eF. Dordoni, Arch. int. Pharmacodyn.74, 263 (1947).     

An extremely cadmium-sensitive strain ofChlorella

Summary Growth of 14 strains from fiveChlorella species is rather insensitive towards cadmium. One strain (211-1a) ofC. saccharophila, however, was found to have a sensitivity towards this toxic heavy metal about 100 times higher than that of the other strains ofC. saccharophila.Acknowledgment. For excellent technical assistance I am indebted to Mrs U. Knoch and Mrs E. Weitemeyer.     

New contribution to the study of chromosomes of the European Cryptocephalinae (Coleoptera,Chrysomelidae)

Summary The chromosomes of three species ofPachybrachis and nine ofCryptocephalus chrysomelids were analyzed. The male meiotic bivalent formula ofP. azureus Suffr.,P. catalonicus Burl. andP. petitpierrei Daccordi is 7^II+Xy_r.Cryptocephalus sexmaculatus Ol. andC. vittula Suffr. have 13^II+Xy_p,C. bipunctatus L. 14^II+Xy_r,C. ochroleucus Steph. andC. ocellatus Drap. 14^II+Xy_p,C. crassus 01. 15^II+Xy_r,C. sulphureus 01. 15^II+Xy_p, the same number as inC. fulvus Goeze with 2n=32 chromosomes, whileC. primarius Har. has 19^II+Xy_p. The modal chromosome number inCryptocephalus is 2n=30 (about 60% of spp.), and most species are characterized their small chromosomes. The low variation found in the karyotypes of Cryptocephalinae along with their possible interrelationships with allied chrysomelid subfamilies are also discussed.     

Association of DNA replication with nuclear membrane in larvae ofChironomus thummi

Summary In the larvae ofChironomus thummi, the newly replicating DNA has been found to be associated with the nuclear membrane, as evidenced by the isolation of DNA nuclear membrane complexes (M-band) of³H-thymidine labelled larvae.Acknowledgment. The authors thank Dr D. S. Pradhan for discussions and encouragement.     

Inhibitory effect of halocyamine,an antimicrobial substance from ascidian hemocytes,on the growth of fish viruses and marine bacteria

Summary Halocyamine A, an antimicrobial substance isolated from hemocytes of the solitary ascidianHalocynthia roretzi, inhibited in vitro the growth of fish RNA viruses (infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus). Pretreatment of RNA virus with halocyamine A reduced the infectivity of the virus toward host cells. The growth of marine bacteria,Achromobacter aquamarinus andPseudomonas perfectomarinus, was also inhibited by halocyamine A but that ofAlteromonas putrefaciens andVibrio anguillarum was not. These results suggest that halocyamine may have a role in the defense mechanisms ofH. roretzi against marine viruses and bacteria.     

The karyotype,C-bands and AgNO3-bands of a lungless salamander from Korea:Onychodactylus fischeri (Boulenger) (Amphibia,Urodela)

The karyotype of a lungless salamander,Onychodactylus fischeri, from Korea was analyzed and compared with that of the Japanese congeneric species,O. japonicus. In both species the diploid karyotype consists of78 chromosomes, including 6 pairs of large chromosomes, 6 pairs of medium-sized ones, and the remaining 27 pairs of microchromosomes. The chromosome number ofO. fischeri, 2n=78, is, like that ofO. japonicus, the largest so far reported in the order Urodela. C-banding showed that constitutive heterochromatin inO. fischeri was mainly in the centromeric regions and near the secondary constrictions of the large chromosomes. AgNO₃-bands were located in the secondary constrictions associated with C-band heterochromatin.     

IAA oxidase activity in relation to adventitious root formation on stem cuttings of some forest tree species

Summary IAA oxixase activity was very high in stem cuttings ofSalix tetrasperma andPopulus robusta, which rooted profusely, less in stem cuttings ofHibiscus rosa sinensis which rooted less, and insignificant in those ofEucalyptus citriodora which did not root at all. Protein(s) extracted from the stem cuttings ofE. citriodora inhibited the activity of IAA oxidase as well as root formation on hypocotyl cuttings ofPhaseolus mungo. The possibility of involvement of IAA oxidase activity in the process of adventitious root formation is discussed.The research has been financed by a grant from U.S. Department of Agriculture.     

Host trail following by the guest antFormicoxenus provancheri

Formicoxenus provancheri, a guest ant ofMyrmica incompleta, is able to follow artificial trails made with the poison gland secretion of its host. The trail-following response is elicited at the same range of concentrations as for the host species. The performance ofFormicoxenus is enhanced by the presence of the host. The adaptive value of these phenomena is discussed.     

Purification and properties of a heat-resistant exotoxin produced byMacrophomina phaseolina (Tassi) Goid in culture

Summary A partially purified preparation of a water-soluble, heat-resistant, nonspecific exotoxin produced by a strain ofMacrophomina phaseolina, isolated fromPhaseolus mungo L. could reduce Cu⁺⁺ ions and produced a red colour with 2,4-dinitrophenyl hydrazine reagent. It caused inhibition of seed germination, wilting of cut seedlings, stunted growth of young seedlings and loss of permeability of the cell membrane. Seedlings ofP. mungo, grown in presence of the toxin showed a slight increase in the contents of protein and total RNA over control, but a significant increase in the specific activities of F-1, 6-BP aldolase and G-6-P isomerase.     

Vegetation structure and primary production in acidified lakes in southwestern Sweden

Summary Research during the last two decades has clearly pointed out that dramatic ecosystem changes have occured in lakes due to deposition of acid substances and decreased pH. Today a large number of lakes and running waters in Scandinavia are suffering biological damage with disappearing fish populations, overgrowth of the bottom by mosses and filamentous algae, reduced invertebrate fauna, increased transparency etc.—Of all documented biological changes the effect on macrophyte succession, in particular that ofSphagnum, is the most striking effect. Along with the growth of filamentous algae, these changes have brought about major shifts in the composition of the primary producers. The biomass in one lake was estimated to be 6.5 t (dry wt) corresponding to about 24 g m^–2, the relevant proportions being 52% forSphagnum, 34% forLobelia and 15% forIsoetes. Percentage production in the whole lake is 54% forSphagnum, 29% forLobelia and 17% forIsoetes, which gives an estimated production of 2.9 t yr^–1 or 9 g m^–2 yr^–1.Sphagnum is a recent flora element and its occurrence is related to the acidification of the lakes. The investigations also show that the growth ofLobelia is reduced in acid lakes compared to other oligotrophic lakes due to shading by the benthic mat of filamentous algae, detritus andSphagnum debris.—One can conclude that there are several quantitative and qualitative changes in the macrophyte community which are related to acidification. One can also conclude that liming of lakes cause elimination ofSphagnum and some increase in the production ofIsoetids.     

Zur Pharmakologie von Psilocybin,einem Wirkstoff ausPsilocybe mexicana Heim

Summary The active principle ofPsilocybe mexicana Heim, Psilocybin, is without marked effects on the isolated organs (seminal vesicle, intestine and auricle of the guinea pig; rat uterus) but exerts an actionin vivo which resembles a slight sympathetic stimulation. In unanaesthetized rabbits it produces mydriasis, tachycardia, tachypnea, hyperthermia and hyperglycemia, in unanaesthetized mice mydriasis and piloerection. The EEG (curarized rabbits) after 1–2 mg/kg Psilocybin shows an alerting pattern (disappearance of spindle activity and of slow waves). Spinal reflexes of the cat are predominantly enhanced. However, the motor activity of mice, rabbits and monkeys is unaffected or even slightly depressed. In anaesthetized cats and dogs Psilocybin affects blood pressure and heart rate, the effect depending on dosage and species.     

Avoidance of competition by spruce bark beetles,Ips typographus andPityogenes chalcographus

Bark beetles,Ips typographus andPityogenes chalcographus, attracted by synthetic or natural pheromone to Norway spruce logs,Picea abies, preferred to colonize uninfested logs rather than logs occupied by these beetles, probably as a means of avoiding intra-and interspecific competition. The aggregation pheromone components ofP. chalcographus, chalcogran and methyl (E, Z)-2,4-decadienoate, inhibited the attraction response ofI. typographus to its pheromone components (methyl butenol andcis-verbenol), while the converse was not true. However, verbenone released from colonized bark inhibited pheromonal response ofP. chalcographus.     

Einfluss von elektrischer Stimulation auf Phosphorylase-Aktivität und cAMP-Gehalt in Insektenflugmuskeln vonLocusta migratoria

Summary In half-thorax ofLocusta migratoria, the activity of phosphorylases and the level of cAMP was studied during electrical stimulation of flight muscles. Both phosphorylase activity and cAMP level increased during phasic and tetanic contractions but no exact correlation could be found.

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Der benutzte Szintillationszähler wurde aus Mitteln des Landesamtes für Forschung, Düsseldorf angeschafft.