56 



K. KISHINOUYE. 



A few words about the methods of investigation may be of use. 

 Eggs of later stages were killed by heating in water to 70-80°C., 

 while segmenting eggs were plunged directly in hot water. Heating 

 was stopped when the eggs became somewhat opaque and white. 

 They were then allowed to cool and transferred to 70% alcohol. 

 After 24 hours, they were examined one by one under a dissecting 

 microscope and those with unburst egg-membranes were perforated 

 with the point of a needle to facilitate the penetration of reagents. 

 They were then hardened in ascending grades of alcohol. I have 

 always found this method to be excellent for all spider eggs. 



Staining was done with alcoholic cochineal, picrocarmine, 

 alcoholic carmine, or hasmatoxylin. Alcoholic cochineal and picro- 

 carmine have given best results. It is a remarkable fact that 

 j)araffin penetrates into eggs stained with picro-carmine more easily 

 than into those stained with any other reagent. Alcoholic cochineal 

 proved to be especially good for staining sections on the object glass. 

 Imbedding for section-cutting was done in paraffin. 



Composition of the Freshly Laid Egg. 



The egg has two investing membranes, the inner of which is the 

 vitelline membrane, and the outer the chorion. The external surface 

 of the latter is covered with a crust of minute spherical granules, 

 insoluble in alcohol. In a species of Epeira, these granules are com- 

 paratively large and closely encrust the surface of the eggs, in some 

 places in two or three layers, making the examination of the inside 

 almost impossible. They were easily removed by gentle rubbing with 

 the fingers. In species of other genera examined, the granules were 

 tolerably crowded in one layer, but being smaller than those of Epeira 

 did not seriously obstruct the view of the inside. 



