Phthinobranchii 231 



delicately at his readiness and ability to defend her children 

 against every enemy, vows unfailing fidelity, and in lover fashion 

 promises as much in a few minutes as would take a lifetime to 

 fulfill. Of course she listens to his suit; personal beauty, 

 indomitable courage, backed by the substantial recommendations 

 of a house ready built and fitted for immediate occupation, 

 are gifts not to be lightly regarded. 



"Throwing herself on her side the captive lady shows her 

 appreciation, and by sundry queer contortions declares herself 

 his true and devoted spouse. Then the twain return to the 

 nest, into which the female at once betakes herself and therein 

 deposits her eggs, emerging, when the operation is completed, 

 by the opposite hole. During the time she is in the nest (about 

 six minutes) the male swims round and round, butts and rubs 

 his nose against it, and altogether appears to be in a state of 

 defiant excitement. On the female leaving, he immediately 

 enters, deposits the milt on the eggs, taking his departure through 

 the back door. So far his conduct is strictly pure; but I 

 am afraid morality in stickleback society is of rather a lax 

 order. No sooner has this lady, his first love, taken her depart- 

 ure, than he at once seeks another, introduces her as he did 

 the first, and so on, wife after wife, until the nest is filled with 

 eggs, layer upon layer, milt being carefully deposited betwixt 

 each stratum of ova. As it is necessary there should be two 

 holes, by which ingress and egress can be readily accomplished, 

 so it is equally essential in another point of view. To fertilize 

 fish-eggs, running water is the first necessity; and, as the holes 

 are invariably placed in the direction of the current, a steady 

 stream of water is thus directed over them." 



To the genus Gasterosteus the largest species belong, those 

 having three dorsal spines, and the body typically fully covered 

 with bony plates. Gasterosteus aculeatus inhabits both shores of 

 the Atlantic and the scarcely different Gasterosteus cataphractus 

 swarms in the inlets from southern California to Alaska, Siberia, 

 and northern Japan. Half -naked forms have been called by 

 various names and one entirely naked in streams of southern 

 California is named Gasterosteus williamsoni. Its traits are, 

 however, clearly related to its life in fresh waters. 



In Pygosteus pungitius, a type of almost equally wide range, 



