Detection of Epstein-Barr Viral Genome in Nonproductive Cells

Hybridization experiments have shown that EB viral DNA comprises between 0.06 and 1.6% of the total DNA of Burkitt lymphoma cells and established leucocyte cell lines.     

The repellent effect of two pyrethroid insecticides on the honey bee*

ABSTRACT. . An improved model for the repellent effect of pyrethroid insecticides on insects was developed using small colonies of honey bees, Apis mellifera L., in flight cages. Conditioning to scented feeders allowed the separation of foraging bees from a single colony into paired treatment and control groups. The repellent response was characterized as a sublethal toxic effect resulting in transitory inhibition of activity. Permethrin and cypermethrin were shown to be contact repellents to honey bees; exposure was primarily to the tarsi and abdominal venter. Repellency was fully reversible within 24 h. No permanent effects on either memory function or foraging efficiency were observed following acute exposure.     

Observations on Mexican Rana pipiens

Mexican Rana pipiens now commonly sold in the United Statesdiffer morphologically and physiologically from their northerncounterparts. They resemble Arizona pipiens in appearance andbehavior, but their breeding cycle is distinctive. They aremost reproductively active in July and August. During late springand summer they can be ovulated readily and their pituitarygonadotropin levels are apparently high. Such is not the caseduring other times of the year. The role of Mexican frogs inteaching and research is discussed.     

The Occurrence, Growth-Temperature Relations and Nuclear Cytology of Protostelium mycophaga Olive and Stoianovitch

SYNOPSIS. Protostelium mycophaga Olive and Stoianovitch was isolated from 7 of 19 plant sources collected in a 15-mile radius of Syracuse, New York. Two of these isolations were made from up-right, nondecomposed plants. Spore diameter measurements of 4 of the isolates gave values that agree with those published for this species. The optimum temperature for the growth of P. mycophaga on enriched corn meal agar and Rhodotorula mucilaginosa was 20 C. Limited growth occurred at 10 C and no growth was observed above 30 C.
Mitosis is described from observations on living and stained preparations.