262 T. IWAKAWA. 



Schwanz gebildet hatte und audi das Weibchen eine 

 starkere Kammauschwellung zeigte, schwaramen beide 

 neben einander her, jedoch so, dass ihre Kopfe entgegen- 

 gesetze Richtuiig batten. Die Schwanze beider waren im 

 Halbkreise gebogen und beriihrten sich mit den Spitzen, so ■ 

 dass das Paar die gestalt eines S. darbot. 



" Wahrend die so verbundenen Schwanze lebhaft hin und 

 her virbrirten, sah man die Kloake des Weibchens dentliche 

 Schluckbemegungen machen, Durch die Vibration gelangte 

 der niannliche Samen an die Kloake des Weibchens und ' 

 wurde von dieser aufgenomen. 



" Die Tritonen legen also nicht, wie viele Amphibian, 

 unbefruchtete Eeier." 



The manner of Depositing the Egg. 



Only one egg is laid at one time — precisely how often I 

 have not ascertained. The eggs of those specimens kept 

 under observation were generally deposited during the night 

 or early morning on water plants. I have sometimes found 

 eggs on dead leaves at the bottom of ponds, ditches. Sec. 



During the act the female generally turns upside down^ 

 seizes the plant by the hind feet, gathering the leaves around 

 the cloacal orifice, which is protruded and brought into con- 

 tact with the plant. In this position the egg is ejected and 

 fixed on the plant by means of the outer gelatinous envelope, 

 which is quite sticky when it first comes in contact with the 

 water. 



The entire act lasts about five minutes. The purpose of 

 turning upside down seems to be to place tlie egg in a con- 

 cealed position under the leaf or stem. 



TJie Structure of the Ovary. 



The ovaries of Triton are a pair of elongated closed 

 sacs, tapering slightly towards either end, the hind ends, in 

 our species, bending forwards. From the inner surface of 

 the thin wall project eggs in various stages of growth. 



For obtaining surface views — which have been of more 

 use than sections in determining the origin of the ova — I 

 have employed silver nitrate and mounted in glycerine. 



Before mounting, all the larger opaque eggs were carefully 

 removed by the aid of needles, leaving only the thin wall 

 with small and transparent ova. 



Silver nitrate, while it browns the protoplasm of the epi- 

 thelial cells and blackens their boundaries, leaves the nuclei- 

 for a time transparent, and inclining to a milky whiteness. 



