POSSIBLE ECONOMIC SIGNIFICANCE 389 



basing their views on past records and much current opinion, see in the 

 presence of such parasites merely an interesting phenomenon. 



For example, it is now found that the presence of nemic parasites 

 not infrequently has a profound effect upon the reproductive organs 

 of the host, a limited number of the parasites even producing complete 

 sterility in a host otherwise apparently normal. That such cases in their 

 most definite form have thus far been found mainly in the invertebrate 

 phyla does not invalidate the application of the idea to vertebrates, 

 even were such cases wholly unknown in the vertebrata, which 

 they are not. Considering the well known universal specificity of 

 certain chemical reagents, chloroform for instance, a "universal" 

 anaesthetic, we should be prepared to accept without very much 

 surprise some such universal specificity in the action of some hormones, 

 particularly sexual hormones, whose origin traces back to comparatively 

 simple, but fundamental, ancestral cell phenomena. 



Again, there is abundant evidence of high infant mortality in a great 

 variety of animals and plants, due to nematism. This, coupled with 

 our ignorance of the early life histories and food habits of fishes, even 

 common ones, makes it unwise to ignore the possible economic impor- 

 tance of the nemic parasites of fishes. 



Many other examples could be cited of the multitudinous and 

 unexpected ways in which nemas are being shown beneficial or in- 

 jurious to mankind. 



Ascarophis helix n. sp. 



fed ?/ "bio ""*&" Sgl-ia* i. The thick layers of the 



transparent, colorless, naked cuticle are traversed by obvious plain transverse 

 striae, which vary markedly in different portions of the body. On the head, 

 however, the transverse striae are hard to resolve; yet critical examination 

 of the striae immediately on and behind the lip region even resolves them 

 into rows of dot-like elements. In this region the crenations of the contour 

 seem duplex, four double crenations a short distance behind the head occupy- 

 ing 10 microns, so that each crenation encompasses about 1.25 microns. 

 In the latitude of the nerve-ring the striae are 1.7 microns apart; thence 

 backward they are gradually coarser and more distinct, each striation 

 becoming a double line. Furthermore, it is soon apparent that the stria- 

 tions pass around the body in the form of right-handed helices coarser and 

 coarser, and more oblique, with increasing latitude, so that at the base of 

 the long neck the coils are about 8 microns apart and lie at an angle of 

 about 23 with a transverse plane. This obliquity increases until, near the 

 middle [of the body, it reaches a maximum of about 30 (Fig. 2). Thence 

 onward, however, the obliquity diminishes. Somewhat behind the middle 

 of the body, certain coils of the helix fade, so that the other, now more promi- 

 nent, striae are as much as 20 microns apart, while their width is nearly 

 two microns, namely the distance apart of the double "lines" representing 

 the striae. This "dropping out," or fading, of course, is evidence of the exis- 

 tence of a plurality of helicoid "striae." In this way the body of the nema takes 



