MODES OF REPRODUCTION 321 



absorb this gas from the vascular filaments which are perhaps 

 in contact with them. 



The habits of the North American bony-pike, Lepidosteus, 

 in the spawning season were described by Mr. S. W. Garman 

 in 1878 from observations made at Black Lake, Ogdensburg, 

 in the State of New York. The lake is connected with the 

 river St. Lawrence. Although there are many Lepidosteus in 

 the lake they are seldom seen except in the spawning season, 

 between 15th May and 8th June, remaining at other times in 

 deep water. The eggs are deposited on irregular heaps of 

 granite fragments which form the extremities of small promon- 

 tories projecting from the shore. The temperature was 68° to 

 69°F. Usually a female swam to and fro with a male against 

 each side with his beak reaching toward the back of her head. 

 After moving slowly to and fro for some time the fish would 

 suddenly lash about violently scattering eggs and milt. The 

 eggs were adhesive and attached themselves with great tenacity 

 to the rocks. The males are much smaller than the females, 

 the largest of the latter sex taken was 4 ft. i£ in. long. On 

 31st March multitudes were seen in all places of the character 

 described, they remained only two days. When they were in 

 the shallow water the fish were seen to rise frequently to the 

 surface and take a gulp of air, opening the mouth widely and 

 closing it with a snap. The eggs were 5 mm. in diameter. 



One species of bow-fin, Amia calva, is extremely common 

 in the lakes and rivers of the Eastern States of North America, 

 for example in Lake Erie, the lakes of New York State, and 

 in South Carolina. It exhibits distinct sexual differences, the 

 male, as is usual in fishes, being considerably smaller than the 

 female; the latter may attain a length of four feet and a weight 

 of thirty pounds while the male is only about two-thirds as large, 

 more slender and lighter in proportion. In April and May the 

 mature fish come from the deep water to the reedy shallows to 

 spawn. The ova are deposited in definite nests made by the 

 removal and beating down of the rushes over a circular space, 

 so that the sunlight shines directly on the ova. When prepar- 

 ing the nest the fish actually bite off rushes which they wish to 

 remove and even floating fragments are carried away so that 

 the surface above the nest is kept clear. The spawning parties 

 are stated to consist of a single female accompanied by several 



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