5IO KNOWER. [Vol. XVI. 



attached to the chorion, at times might be mistaken for bunches 

 of filiform bodies. When such specimens are crushed, the 

 membrane wrinkles up and looks like bunches of filaments. 

 The eggs from one nest had been attacked by fungus to such 

 an extent that the hyphae, entering the micropyles, had rami- 

 fied in the yolk and used it up, destroying the embryos. Dr. 

 Hagen could hardly have confused such large objects as these 

 hyphae with spermatozoa. As sperm failed to appear in any 

 of my stained specimens, I am inclined to think that folds in 

 the membranes or strands of protoplasm were mistaken for 

 spermatozoa. 



The Yolk. 



My observations on the yolk were made on preserved 

 material. The yolk-mass, thus studied, is composed of a lot 

 of polygonal bodies, which are vesicles containing a homoge- 

 neous coagulable fluid. These bodies stain deeply in haema- 

 toxylin and carmine, and very considerably in size and shape 

 {PI. XXXI, Figs. 30-37, yb.). The other constituent of the yolk- 

 mass is an oily fluid distributed in small globules throughout 

 the egg, and often found collected in one or two quite large 

 drops. When alcoholic specimens are crushed, the oil globules 

 flow together and run out, leaving the yolk-bodies for the most 

 part intact. In such cases the character of the vesicles can be 

 made out. They are found to vary in structure, part of them 

 being filled entirely with homogeneous coagulable substance 

 quite elastic under pressure. 



Many of the bodies, however, differ from this. They contain 

 the homogeneous stainable substance, but also little oily drops, 

 of which there may be only a few or a great number in a 

 vesicle. The greater the collection of these drops, the less is 

 the homogeneous material, so that it is often reduced to a 

 porous substratum for the drops. It is possible to crush such 

 vesicles so that the oil drops escape through the membranous 

 walls. Examined in clove oil or in sections the yolk has quite 

 a different appearance. In these specimens the oily matter is 

 all dissolved out of the yolk, even from the interior of some of 

 the vesicles. Treatment with oils and subsequent heating dur- 



