496 ROBERT W. HEGNER 
Amma ’11), and in Sagitta (Elpatiewsky ’09, ’10; Buchner, 
10 a, 710 b; Stevens 710). The other period is that of the differ- 
entiation of the oocytes and nurse cells in the female and, at least 
in man, of the ditferentiation of the spermatocytes and Sertoli 
cells in the male (Montgomery ’11; Winiwarter 712). These two 
periods seem rather distantly removed from each other, since we 
ordinarily begin our ontogenetic studies after the eggs are laid, 
but in reality they are very close together in the germ-cell cycle 
since the oocytes and nurse cells often become differentiated 
shortly before the deposition of the eggs, and the primordial 
germ cells are segregated shortly after cleavage begins. 
This contribution deals entirely with the second period de- 
scribed above and the data have been derived from a study of the 
cellular elements in the ovaries of the queen honey-bee, Apis 
mellifica. Bees of three ages were employed: (1) those still 
within their pupal cells, (2) virgin queens three days old, and 
(3) virgin queens shortly before the deposition of eggs. The 
ovaries were dissected out in Ringer’s solution and fixed in five 
different fluids: (1) Towers’, (2) Carnoy’s, (3) Bouin’s, (4) 
Altmann’s, and (5) Meves’ modification of Flemming’s solution. * 
1 The formulae are as follows: 
(1) Tower’s solution. 
Saturated sol. HgCl, in 35 per cent alcohol..................2... 95 vols. 
Glacial Sacetichacid) yy Rare eee oc =. 2 Oe eee 2 vols. 
IN asia CLE GZie.< sta csete ae RNS Ree, cs (n=, <a wo Ae 3 vols. 
(2) Carnoy’s solution. 
Absolutefaleohol??.). ea eee ene -L ns teen eee 1 vol. 
Glacraltacetie’ acid 3! Meaeppsew cs karst: kai see eee 1 vol 
Chl OROLOTM.¢-48 Gis se Nee EEE el os. cok SEE Le ee 1 vol 
HegCl, to saturation 
(3) Bouin’s solution 
Picrie acid, (Sat. aqueotis; Bolle ns... J... «cad Ree ee 75 vols. 
Pormol 9.) 2.4.) SS eisai eee c/s 5.53 ss ck ba boa 25 vols. 
Glacial; acetic acid’) 2.02 eee emer >. oss eee eee 5 vols. 
(4) Altmann’s solution 
Bichromate. of potash, 5 penmwenteh.., 02 0%... 3... a eee eae 1 vol. 
Osmic) acid, 2 percent: Vaase epee ee Cs. J oe 1 vol. 
(5) Meves’ solution 
Osmie acid, 2 per cent. ve see nei - toes: ss) ee ee ee 100 ce. 
Chromic aerd. «ici! <0 1a OS «foe so ei ee ee eee O.oiee 
IN Cres hehehe soe ak pce ee roe ic titne i. ott eae ee 1 gram. 
