DNA synthesis in the follicular cells ofCarausius morosus Br. (Phasmidae)

Riassunto Le cellule follicolari di un medesimo follicolo hanno nuclei che diversificano notevolmente fra loro per il volume. Ciò è ben osservabile nelle sezioni trasversali dove i nuclei, di forma cilindrica, appaiono circolari. La timidina tritiata viene incorporata preferenzialmente nei nuclei più piccoli. Per spiegare tale fenomeno è stata fatta l'ipotesi di una fase di accrescimento nucleare in assenza di sintesi di DNA.     

Polarity and symmetry in composite oocytes ofCarausius morosus Br. (Cheleutoptera,Phasmidae)

Zusammenfassung Der Follikelbau mit mehreren Oocyten in den panoistischen Ovariolen vonCarausius morosus wird beschrieben. Die Follikelentwicklung ist polar oder apolar und die Oocytenkerne konzentrieren sich bei rotations- oder bilateralsymmetrischem Oocytenkomplex.     

Bewegungsmimikry beiCarausius morosus Br. (Phasmida)

Summary Larvae and imagoes ofCarausius execute rhythmic swinging movements with their whole body at higher temperature and high atmospheric moisture. These are used for the regulation of the body temperature.These swinging movements are regarded as moving-mimikry, because it could be shown that walking sticks which went straight on were significantly more often found and eaten by chickens than swinging animals.     

Free amino acids of the hemolymph ofAnacridum aegyptium L. (orthoptera)

Riassunto Sono stati determinati 14 aminoacidi liberi nell'emolinfa: di cssi acido glutamico, glicina e prolina rappresentano insieme il 50% e più del contenuto totale. Le ninfe verdi contengono meno glicina e acido aspartico e più treonina e fenilalanina in confronto alle ninfe brune. Gli individui adulti mostrano in contenuto relativo di aminoacidi diverso dalle ninfe e fra i due sessi. Somministrazione di triptofano a ninfe brune non ha dato variazioni negli aminoacidi liberi, non aumento dell'aminoacido stesso, né presenza di prodotti del suo metabolismo nel sangue.     

Melanocyte precursor cells in the hair follicle germ during the dormant stage (telogen)

Zusammenfassung Der Ursprung der Melanozyten, die in der Haarwurzel während jedes Haarzyklus erscheinen, ist bisher unbekannt gewesen. Helle dendritische Zellen im ruhenden Haarkeim, welche an der Haarpapilla liegen, die sich während der frühen Anagen teilen und während Anagen III–IV Farbkörperchen hervorbringen, sind augenscheinlich die Vorläufer der Haarmelanozyten.     

Studies on peripheral neurons and neurohaemal tissue in the thorax of the stick insect (Carausius morosus)

Summary The distribution of peripheral neurosecretory and non-neurosecretory neurons, and transverse nerve neurohaemal swellings, is described in the thorax ofCarausius morosus. The electrical activity of the isolated transverse nerves has been recorded.We are grateful to the Science Research Concil for financial support, and to Dr Sue Fifield and Steven Irving for methylene blue and electron microscope preparations.     

Origin of ovarian follicle cells in birds

Summary In the embryonic Japanese quail ovary, transplanted on chicken chorioallantoic membrane (CAM), follicle cells are derived from somatic cells of the ovarian surface epithelium. No evidence was found for a contribution of other cell groups of the quail ovary in the formation of follicle cells. This may be demonstrated on PAS stained sections, by following the transfer of carbon particles, initially applied on the surface epithelium.The author is very grateful to Prof.L. Vakaet, R.U.C.A. Antwerp, for his valuables suggestions, and to MissC. van Hoecke for her technical assistance.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Summary Actin-and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.This work was supported by the Swedish Medical Research Council, grant No. 14X-732/5680.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.