322 



THE UNFERTILISED EGG AS A 



[PT. Ill 



Table 32. 



In % of total egg-weight 



Yolk Investigator and date 



— Konig & Grossfeld (191 3) 



3? 33 



75-3 Ford & Thorpe (1920) 

 36-5 Wetzel (1907) 

 — Tichomirov (1882) 



14-0 



3J 



Kronfeld & Scheminzki (1926) 

 Ranzi (1930) 



Tomita's figures. 



Marine turtle ( Thalassochelys cortica) 

 Weight 



Shell 



White 



Yolk 



Total 



m gm. 



2-0 



13-5 

 18-9 



34-4 



% 



5-8 



39-2 



55-0 



Wetzel's figures. 



I Frog {Rana temporaria) 



Ovarial egg (no jelly)... 

 Egg with unswoUen jelly 

 Jelly alone 

 Swollen jelly ... 

 Water content of ovarial egg 

 jelly 

 „ „ egg and jelly 



Empty dry jelly 

 Dry egg 



Dry egg + dry jelly ... 



Thus of dry weight egg 



jelly 



Weight in mg. 



1-897 



4-674 



2-777 



8-97 



0-62 

 0-90 

 1-52 



Melvin's figures. 



Shell-weights of insects 



Squash-bug {Anasa tristis) 

 Luna moth [Tropoeoa luna) 

 Cecropia moth {Sarnia cecropia) ... 

 Smartweed-borer {Pyrausta ainsleii) 



52-5 



78-65 



67-48 



59-28 

 40-72 



% of total 



weight of eggs 



29-2 



23-3 

 22-0 

 31-0 



it was remarkably resistant to putrefaction, and studied the 

 effect of enzymes such as pepsin upon it. The resistance of 

 frog ovomucin to putrefaction was for long a puzzle to bio- 

 chemists, but it seems to be explained by the unwillingness of most 



