1911] Smith. Natural History of Amhy stoma. 19 



tigrinum suggests the possibility of an autumnal fertilization. In 

 this connection it may be mentioned that the testes of an adult 

 A. tigrinum, preserved Sept. 21, 1907, were very large and swol- 

 len with ripe or nearly ripe spermatozoa, while an adult of the 

 same species, taken March 24, 1910, contained no sperm that 

 could be obtained by stripping, and when preserved April 3, 1910. 

 the testes were extremely small as is usual in urodeles after the 

 breeding: season. Sections showed the testes of the latter sped- 

 men to contain very few spermatozoa, and those in a state of 

 degeneration. 



THE EGGS AND THEIR ENVELOPES. 



In all three species the eggs, with their individual gelatinous 

 envelopes, are aggregated in masses by means of a common jelly 

 envelope, which varies greatly in thickness in the different species. 



I have identified the eggs of A. punctatum by obtaining them 

 from a female in captivity; eggs of A. tigrinum through the ex- 

 clusive occurrence of this species at Lake Forest; and eggs of A. 

 jeffersonianum through a process of exclusion. 



In twelve clusters of eggs of A. punctatum the average num- 

 ber of eggs in a cluster was found to be 56, the range 30-95. 

 Clarke ('79) states that the masses "vary in size from a small 

 bunch of three or four eggs to a large mass containing two hun- 

 dreds eggs and weighing sixteen ounces." According to Wright 

 and Allen ('09), the number of eggs in a complement varies 

 from 130 to 225 ; these may be deposited in one to ten bunches, 

 two or three per female being a fair average. 



In 52 egg masses of A. jeffersonianum the average number of 

 eggs was found to be 14, the range 1-35. Piersol ('10) states: 

 "The typical spawn mass of A. jeffersonianum is a small one, the 

 number of eggs being usually about twenty; the extremes en- 

 countered have been small masses of jelly without any eggs, and 

 a mass containing forty-one. The complement of ripe ovarian 

 eggs carried by two females of average size was 128 and 161." 



My notes contain only two records of the number of eggs in 

 the egg masses of A. tigrinum — bunches of 53 and 75 eggs re- 



spectivelv. 



The egg masses of A. punctatum (see Plate II, Fig. 4) aver- 

 age much larger in size than those of either jeffersonianum 



