HYNOBIIDAE. 499 



"Now March is often so cold in Japan, that frost covers the ground 

 in the morning, and on rare occasions it snows. 



"The weather at this season is very variable. . . . Often it turns sud- 

 denly warmer and great quantities of rain fall, thereupon the H 1/710- 

 bius emerge and seek a pool, where they can spawn, and if these 

 weather conditions endure about three days, egglaying takes place, 

 even though it turns cold again afterwards. If, however, the cold 

 sets in again after a very short time, before the Liebesspiel has begun, 

 (after about a day), the animals remain motionless at the bottom as if 

 sleeping, and await a second warm rain. If the weather is very 

 unfavorable for their purposes, e.g. if the pool dries up entirely, they 

 crawl back on land and hide themselves in their former dwelling places. 

 If the pool does not dry up, but there comes a second warm rain, then 

 they swim vivaciously hither and thither, newly awaked, and with 

 them others, which have just come in from the land. Then they carry 

 on their Liebesspiel; thereafter they lay the eggs. 



"This process is repeated three or four times each Spring during the 

 spawning period, if the weather is sufficiently favorable. Naturally, 

 each repetition is by new animals. . . . 



" Warm weather alone is not sufficient Jx>r the process, but there must 

 be at the same time a heavy rain. If this is not the case, even if it 

 is warm enough, no animals appear and no eggs are laid. 



"As early dates for the egglaying I can give the following dates for 

 the last four years: 



1905: March 15: Water Temperature 8 degrees Cent. 



1906: " 25: " " 10 



1907: " 28: " " 7 " " 



1908: " 10: " " 9 



and as late dates: 



1907: April 6: Water Temperature IS degrees Cent. 

 190S: " 1: '" " IS " 



"In 1905 and 1906 they laid only once and in small numbers. . . .When 

 the Hynobius males in warmer localities awake from hibernation, they 

 crawl at once to the nearest place of water and there await the females. 

 The latter come at the same time or at most a few days later, and the 

 animals get into a state of sexual excitement, provided the favorable 

 weather conditions hold. The Liebesspiel then takes place in the 

 following manner. 



"The males and females assemble in groups under a stone, rock or 

 in the shadow of grasses, and swim forwards and back, up and down, 



