THE 



POPULAR SCIENCE 

 MONTHLY. 



MAY, 1877. 



GAE-PIKES, OLD AND YOUNG. 



By Professor BURT G. WILDER, 



OF CORNELL UNIVERSITY. 



SOME readers of The Popular Science Monthly may never have 

 seeu gar-pikes, or even heard of them. The word does not occur 

 in some of the dictionaries, and the animals themselves are found 

 alive only in certain parts of the world. So, before telling what gar- 

 pikes do, it is necessary to explain what they are. 



^1 M ' I n I M 1 1 F 



Fig. 1. The Shokt-nosed Gar-Pike (Lepidosteus plaiysiomus). 

 Nearly adult, one-fourth natural length. O, the gill cover, or operculum. P, the pectoral, and Ve, 

 the ventral, fin of the left side. D and A, the dorsal and anal fins. DF and VF, the " fulcra " 

 which cover the dorsal and ventral borders of the root of the tail. X indicates the point where 

 the eection shown in Fig. 3 was made. The scales are shown in the next figure. 



In the first place, the gar-pike is not a weapon, but a vertebrated 

 animal. The vertebrates include all animals having a spine or back- 

 bone made up of a series of segments or vertebrce. But this common 

 definition is not wholly accurate. For the very young of man and 

 monkeys, quadrupeds and birds, reptiles and fishes, have no skeleton 

 at all ; and some of the lowest fishes, the Amphioxus and the lam- 

 prey-eels, have no bones. So the vertebrates are now said to include 

 all animals having a longitudinal axis or spine (whether membrane, 

 cartilage, or bone) separating an upper or dorsal cavity, containing 

 the spinal cord and brain, from a lower or ventral cavity, containing 



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