45 



and Formica fiisca, but says that they disappear with the formation 

 of the yolk in the €:gg. He found them later ('87 and '92) in certain 

 other insects, and similar bodies have since been found by Forbes 

 (1892) in the c^ecal glands of various Heteroptera, and identified by 

 him as bacteria, and by Wheeler ('89, p. 306) in the egg of Blatta 

 germanica. Recently they have been proved to be bacteria by Mercier 

 ('07), who grew them in cultures. Those I found in C. herculcanus 

 stain deeply with eosin and with methylene blue but do not take the 

 Gram stain. So far as I know this is the first time these bacteria 

 have been seen in ants' eggs in this country. 



The peripheral layer of protoplasm at its inner edges passes out 

 into what appears in sections as a delicate network of protoplasm 

 which extends through the entire egg. This delicate network shows 

 very clearly because of the fact that the protoplasm stains more 

 strongly with hcxmatoxylin while the yolk granules stain more 

 strongly with orange G. Both protoplasm and yolk will take either 

 stain, but the yolk stains much more readily with orange G, while 

 the protoplasm stains much more readily with hrematoxylin, thus 

 producing a very good differentiation. Near the posterior end of 

 the tgg^ and to a less extent near the anterior end, this network leaves 

 many large vacuoles between which occur yolk granules. Near the 

 center of the egg the yolk granules are massed to such an extent that 

 there are very few or no vacuoles. These yolk granules vary in size, 

 and also somewhat in shape, but approach a globular form, and are 

 very finely granular. They range in size from a diameter of about 

 .005 mm. to a diameter of alx)ut .027 mm., with an average diameter 

 of about .018 mm. 



In the peripheral layer of protoplasm at the posterior end of a 

 freshly laid tgg, or of one at a somewhat later stage (one to thirteen 

 hours), is found a very large, much vacuolated, heavily staining 

 nucleus (Figures i and 2). In addition to this, there is found sit- 

 uated very near the large one, in some of the eggs, a much smaller 

 nucleus (Figures i and 3), having the same apj^earance as the large 

 one except that it is generally denser, that is, less vacuolated. In 

 one of my slides the two nuclei were just touching each other. In 

 sections of several somewhat later stages, still more nuclei of exactly 

 the same api>earance were found. These nuclei all had the same 

 appearance structurally. I did not see in those I examined any ap- 

 pearance of karyokinetic figures. Of two eggs killed just after be- 

 ing laid, one contained but the one large nucleus, the other contained 

 the large nucleus and a small one. Of three eggs one hour old, one 

 had only the one large nucleus, one had the large one and one small 



