Effects of precocene II and juvenile hormone III on the activity of neurosecretory A-cells inOncopeltus fasciatus

Summary Application of precocene II, topically or by contact method, appears to inhibit the synthetic activity of neurosecretory A-cells of the pars intercerebralis ofOncopeltus fasciatus. Treatment of precocene-treated insects with JH III apparently stimulates the secretory activity of these cells.Supported by National Research Council of Canada grant No. A4669.We thank Dr G. B. Staal, Zoecon Corporation, Palo Alto, California, for the gift of precocene II.     

Modification of clonazepam anticonvulsive activity by its association with other anti-epileptic drugs

Summary The modification of the anti-epileptic activity of clonazepam by other anticonvulsivants is studied. The results vary according to the drug and technique used. The usefulness of the 2 techniques employed is discussed.     

Does nitrogen mustard mimic the X-ray effects in any case?

Résumé Les effets de l'ypérite nitrée sur le cerveau et yeux de l'embryon du rat blanc ont été analysés. Seulement les embryons présentant un aspect normal ont été coupés et colorés. De larges centres de nécrose ont été trouvés sur les coupes tandis que les «rosettes» n'ont pas pu être décelées.Bien que connue comme radiomimétique, l'yperite nitrée ne mime pas les rayons X en ce qui concerne la formation des «rosettes» dans le cerveau.     

A wide spectrum of resistance to pyrethroid insecticides inMusca domestica

Summary Selection of a strain of house flies with the pyrethroid bioresmethrin has resulted in a wide range of cross resistance to 15 other pyrethroid insecticides.     

Phospholipid composition ofDipylidium caninum

Summary The phospholipid composition ofDipylidium caninum has been studied. Chloroform-methanol-soluble fraction amounted to 2.4% and phospholipids to 0.5% of the wet weight of the parasite. Phosphatidyl choline and phosphatidyl ethanolamine represented the bulk of the phospholipids, whereas phosphatidyl serine, phosphatidyl inositol, lysolecithin and lysophosphatidyl ethanolamine were present in minor amounts. Sulfatides were also identified in this parasite.     

Effect of light adaptation on electrical responses of the retinas of four species of bats.

The levels of light adaptation at which the retinas of 4 species of microchiropteran bats became unable to generate electroretinograms were progressively ordered. The order correlated well with light preferences based on activity patterns of the 4 species. These results suggest that the ability of the retina to function in ambient light may govern some natural behaviors of these bats.