THE EMBRYOLOGY OF THE HONEY BEE 15 



the honey bee but is thicker on the ventral than on the dorsal 

 side. In Camponotus Tanquary mentions a well developed corti- 

 cal layer, containing a large number of Blochmann's corpuscles, 

 and having also embedded in it numerous yolk granules. Vacu- 

 oles, so called, are present at the center of the egg, more espe- 

 cially near its anterior end. Possibly these correspond to the 

 yolk spheres of the honey bee. 



In the descriptions of both Biitschli and Grassi are noted the 

 protoplasmic network, the vitelline spheres, the vitelline bodies 

 and Blochmann's corpuscles. The latter, it is true are not 

 specifically mentioned, but the protoplasm is spoken of in both 

 instances as "granular," an appearance referable to the presence 

 of these bodies. These investigators also observed the cortical 

 layer, describing it also as "granular." 



As regards the chemical make-up of the deutoplasmic portion 

 of the insect egg, very little is known. It is commonly described 

 as consisting of yolk and oil globules. This paucity of informa- 

 tion is no doubt due to the fact that embryologists usually have 

 not the training requisite to enter the difficult field of micro- 

 chemistry. It is true that Tichomiroff (1885) made an elabo- 

 rate chemical analysis of the silkworm egg, but this work has 

 apparently stood alone. Friederichs (1906) subjected the con- 

 tents of the egg of Rhagonycha and Chrysomela to a few simple 

 reagents : water, normal salt solution, an aqueous solution of 

 osmic acid and mercuric chloride, and diluted hydrochloric and 

 acetic acids combined. The results convey but little information 

 concerning the real nature of the deutoplasm except to demon- 

 strate the presence of oil droplets. The presence of these ap- 

 pears to be quite general in insect eggs. Grassi assumed that 

 the vitelline spheres in the egg of the honey bee are of an oily 

 nature ; a natural supposition, suggested by their appearance. 

 Repeated tests with osmic acid, however, failed to yield the 

 well known blackening reaction characteristic of fat, nor did 

 other elements in the egg show it. The egg of the bee therefore 

 is presumably totally devoid of fat or oil, as such. A few tests 

 with other reagents were applied to the vitelline spheres, but with 

 inconclusive results, except that they appear to indicate that the 

 vitelline spheres in the bee are similar to those in the eggs ex- 

 amined by Friederichs. 



