456 



SCIENCE. 



[N. S. Vol. XIX. No. 481. 



of Phascalosoma. Ida Hyde has examined 

 the eyes of Pecten with the aid of modern 

 neurological methods, and concludes that our 

 previous interpretation of the function of 

 some parts must be erroneous. H. B. Ward 

 gives a detailed account of several larvte of 

 the hot fly, Dermaiohia hominis, which occur 

 as parasites in man and other warm-blooded 

 animals in the tropics. 



Two papers deal with the Tunicata. Will- 

 iam E. Ritter has a new tunicate, Herd- 

 mannia claviformis, from California, the an- 

 atomy of which is detailed and some facts 

 concerning its development are given. It ap- 

 parently belongs near Amaroucium, but must 

 form a new family. P. W. Bancroft found a 

 colony of Botryllus at Naples which partly 

 died down and then exhibited rejuvenescence. 

 The physiology and the structural changes in- 

 volved are described, the author concluding 

 that deficient nutrition was the cause of the 

 phenomena observed. 



H. V. Neal and W. A. Locy both deal with 

 the nerves of sharks. Neal describes the 

 method of the formation of the ventral roots 

 of the spinal nerves, analyzing the fates of 

 various cellular elements which have been, de- 

 scribed in the cord, and concluding that all 

 the neuraxones are formed from medullary 

 cells and that the cells of the ventral nerves 

 are concerned alone in the formation of the 

 neurilemma and possibly some of the con- 

 nective tissue. Locy returns to his ' new 

 nerve,' which parallels more or less closely the 

 olfactory nerve. He has now found it in 

 nineteen genera of elasmobranchs, but finds 

 no traces of it in the teleosts and amphibians 

 which he has studied. P. C. Sargent takes 

 for his contribution an account of that pe- 

 culiar structure, the torus longitudinalis of 

 the teleost brain, which he shows is nervous in 

 character and serves as a center for the re- 

 ceipt of those impulses from the optic nerves 

 which call for quick reflexes. 0. H. Eigen- 

 mann has been fortunate enough to obtain 

 eggs of the blind ,fish, and he has given here 

 an account of the development and degenera- 

 tion of the eye. 



E. M. Strong shows that the metallic colors 

 of the feathers on the neck of the domestic 



pigeon can not be explained as produced by 

 diffraction spectra or by refraction prisms, but 

 that they must arise as thin plate interference 

 colors produced between the contained spher- 

 ical pigment granules and the outer trans- 

 parent layer of the feathers. 



Thomas G. Lee presents a paper on the 

 fixation of the ovum in the striped gopher, 

 Spertnophilus tridecemlineatus, the first of a 

 series on the development of this form. The 

 details are not readily presented in abstract, 

 but it is shown that this foi-m differs from all 

 other mammals in the temporai-y fixation mass. 



The only paleontological paper is by C. E. 

 Eastman upon the peculiar selachian fossils, 

 EdestiLS and its allies, which are known chiefly 

 by a peculiar series of structures, often in- 

 terpreted as spines, but now shown to be a 

 coiled series of symphysial teeth, the struc- 

 tures reaching their extreme in Helecoprion. 



The subject of variation is treated in two 

 papers by Dr. and Mrs. C. B. Davenport. 

 Dr. Davenport compares the variability of the 

 scallops from Florida and from southern Cali- 

 fornia, showing that the latter are much more 

 variable and correlating this with the more 

 varied environment and the greater geological 

 changes on the Pacific coast. Mrs. Davenport 

 has studied the number of stripes in the sea 

 anemone, Sagartia leucolena, and concludes 

 that their number is in part due to longitudinal 

 fission. She also confirms the observations of 

 Torrey and Parker which show that the mono- 

 glyphic conditions so frequently found in nor- 

 mally diglyphic hexaetinians are to be ex- 

 plained by the same type of asexual reproduc- 

 tion. 



The two physiological papers, by G. H. 

 Parker on the phototropism of Vanessa an- 

 tiopa and by E. M. Terkes on the reactions of 

 Daphnia to light and heat, hardly admit of 

 summary. Parker shows that Vanessa creeps 

 and flies towards the light, but comes to rest 

 with its head away from strong light. When 

 the eyes are blackened all phototropism ceases. 

 It is not affected so much by strength of light 

 as by the size of the light area, and its retreat 

 at night is largely dependent upon tempera- 

 ture changes. In Daphnia, according to 

 Yerkes, phototropism occurs with light of all 



