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THE AMERICAN NATURALIST [Vol. XLIII 



oviposition by pulling the eggs strings with his toes. 

 That the male ejects his sperm at this time was demon- 

 strated by microscopical examination of a slide applied 

 to the anus of the male just before and during oviposi- 

 tion. In the former case, very few if any spermatozoa 

 were found, while, in the latter, they were found in 

 abundance. 



As soon as the eggs and sperm are ejected the toads 

 remain quiet, holding the mass in the improvised basket 

 perfectly quiet from one to three minutes. This is ample 

 time for the spermatozoa to get well attached to the eggs, 

 since fertilization takes place within four minutes from 

 the time the eggs leave the oviduct. The female now 

 moves along, stretching out the strings of eggs just laid. 



Most of the eggs are deposited in water not more than 

 ten inches deep. Those found in weedy and grassy places 

 are, usually, not over four inches under water. In Uni- 

 versity and Elm Park ponds where the toads were much 

 disturbed, a large number of eggs was deposited some 

 distance from the edge at a depth of eighteen inches or 

 more. This deep laying seemed of no particular dis- 

 advantage, since a toad can remain underwater as long 

 as fifteen minutes, which is ample time to fertilize the 

 eggs and stretch out the egg strand. 



The eggs are encased in a continuous, cylindrical, gel- 

 atinous strand of three to four millimeters in diameter. 

 The gelatinous coat is added in the oviduct, and as soon 

 as ejected absorbs water and swells. In this way there is 

 a mass of .0225 gram of jelly-like substance about each 

 egg, which serves as a means of protection. Eggs re- 

 moved from the ovary weigh on an average .0024 gram 

 and measure 1.1 to 1.2 mm. in diameter. When laid 

 they are variously spaced in the strands even of the same 

 spawn (Fig. 4). Sometimes they are crowded together 

 so that as many as three may be in the same cross-section, 

 or -again regularly spaced at intervals of about 1 mm. 

 lhe strings may be laid by either twos or fours. I have 

 not observed in smaller toads (under 7 cm.) more than 

 two strands being deposited at the same time, but in the 



