Experimentally induced encapsulation ofDiplostomum phoxini (Faust) in the fish host

Summary Experimentally induced encapsulation ofDiplostomum by the hostPhoxinus, is recorded for the first time and requires the metacercariae to develop in fish at a temperature (23–26°C) which is above that naturally encountered.Acknowledgment. It is a pleasure to thank M. R. L. Johnston for his advice.     

Mast cells in nerves affected with fowl paralysis (marek's disease)

Zusammenfassung Bei der spontanen Marekschen Hühnerlähmung, die durch Ödembildung und Ablagerung von Mucopolysacchariden und Collagen zwischen den Nervenfasern gekennzeichnet ist, erhöht sich auch die Anzahl der Mastzellen bedeutend. Es zeigt sich, dass Nerven, die eine neoplastische Infiltration mit primitiven lymphoiden Zellen aufweisen, weniger Mastzellen als gesunde enthalten. Zur Identifizierung der Mastzellen wurde auch das Elektronenmikroskop verwendet.     

Detection of nerve cells by a histochemical technique

Riassunto Viene descritto un procedimento istochimico di utile impiego per l'evidenziazione e il conteggio di cellule nervose, particolarmente in alcuni distretti del sistema nervoso autonomo. Per l'alta penetrabilità del substrato è possibile applicare il metodo su preparazioni in toto ed avere quindi una elevata precisione nelle determinazioni del numero e del volume delle cellule nervose.     

Mast cells and histamine in a newt,Triturus pyrrhogaster boié

Zusammenfassung Es wird nachgewiesen, dass die Mastzellen vonTriturus pyrrhogaster Boié kein Histamin enthalten, sie also im Gegensatz zur allgemeinen Annahme keine Histamozyten sind. Dieser Befund wurde sowohl biologisch am Meerschweinchendarm durch Extraktion des Histamins mit Hilfe der Codeschen Methode als auch durch den histochemischen Histaminnachweis mito-Phthalaldehyd an verschiedenen Geweben bestätigt.     

Neurosecretory cells in the ventral nerve cord of leech (Hirudinaria granulosa)

Zusammenfassung Nachweis von 3 Typen neurosekretorischer Zellen im Bauchmark der indischen BlutegelHirudinaria granulosa undTheromyzon rude.     

Mast cells in the pinna of Balb/c 'nude' (nu/nu) and heterozygotes (ny/+)mice.

The relative number of mast cells in the ear lobes' skin (pinna) of nude (athymic) nu/nu and normal (thymic) nu/+ heterozygotes of Balb/c mice was similar. The results obtained contradict some suggestions about the general influence of the thymus on the number of mast cells in the skin and suggest the existence of some local factor(s) in regulation of skin mast cell numbers.     

Phytoalexin response is elicited by a pathogen (Rhizoctonia solani) but not by a mycorrhizal fungus (Glomus mosseae) in soybean roots

Summary A container system was constructed to study the response of soybean roots to infection by mycorrhizal or pathogenic fungi. The system allows a rapid and synchronous inoculation byGlomus mosseae orRhizoctonia solani. The phytoalexin glyceollin was measured in roots of inoculated and uninoculated plants for a period of 30 days. A significantly increased content of phytoalexin was found inR. solani-infected roots as compared to uninfected control roots. However, there was no difference in the glyceollin contents of the mycorrhizal and the control roots for up to 23 days after inoculation. The accumulation of glyceollin inR. solani-infected roots was not influenced by a subsequent inoculation withG. mosseae. Moreover glyceollin accumulated in mycorrhizal plants to the same extent as in control plants when they were inoculated withR. solani. The two fungi did not mutually influence the course of infection when they were inoculated together.     

Mast cells in the pinna of Balb/c ‘nude’ (nu/nu) and heterozygotes (nu/+) mice

Summary The relative number of mast cells in the ear lobes' skin (pinna) of nude (athymic) nu/nu and normal (thymic) nu/+ heterozygotes of Balb/c mice was similar. The results obtained contradict some suggestions about the general influence of the thymus on the number of mast cells in the skin and suggest the existence of some local factor(s) in regulation of skin mast cell numbers.This work was supported by grant No. CA16426.The author wishes to thank Dr Kenneth Morrison for supplying the mice and the discussion, Mr Duffy Michowski for taking care of the animals used, Mr Carl Polley for taking the pictures and Dr N. R. Rose for the discussion.     

Inhibition of temperature-induced spermatogenic proliferation by a brain factor in hibernatingHelix aspersa (Mollusca)

Summary Ablation of the brain from hibernatingHelix aspersa maintained at 25°C causes a significant increase in the proliferation of male cells in the gonad, whereas the ablation of the optic tentacles has no effect. The brain, therefore, produces a factor which specifically inhibits the multiplication of spermatogonia and spermatocytes.     

Inhibition of temperature-induced spermatogenic proliferation by a brain factor in hibernating Helix aspersa (Mollusca)

Ablation of the brain from hibernating Helix aspersa maintained at 25 degrees C causes a significant increase in the proliferation of male cells in the gonad, whereas the ablation of the optic tentacles has no effect. The brain, therefore, produces a factor which specifically inhibits the multiplication of spermatogonia and spermatocytes.     

Alloglossidium anomophagis sp. n. (Trematoda: Plagiorchiidae) exhibiting progenesis in water fleas (Anomopoda: Daphniidae)

The trematode,Alloglossidium anomophagis sp. n. (Digenea: Plagiorchiidae) exhibits progenesis in water fleas of the genusDaphnia (Anomopoda: Daphniidae) occurring in temporary rainwater-filled ditches near Houston, Texas, USA. We assume thatA. anomophagis has achieved its truncated life cycle by eliminating the vertebrate which originally served as the definitive host. The adults ofA. anomophagis represent the smallest trematodes in the family Plagiorchiidae, measuring less than 0.5 mm in length.     

The response of frog taste cells (Rana nigromaculata andRana catesbeana)

Zusammenfassung Die Registrierung der Rezeptorpotentiale einzelner Geschmackszellen von Raniden (R. nigromaculata undR. catesbeana) bei Reizung mit 4 Grundgeschmacksarten mittels Glasmikroelektrode ergibt: Ruhepotential der Rezeptorzellen 10–35 mV (innen negativ). Die einzelnen Geschmackszellen antworten auf mehr als 2 Geschmacksarten und zeigen im Hinblick auf ihre Antwortmuster zellcharakteristisches Verhalten.