NATURE 



169 



THURSDAY, DECEMBER 22, 1904. 



A ZOOLOGICAL TRIBUTE. 

 Mark Anniversary Volume. To Edward Laurens 

 Mark, Hersey Professor of Anatomy and Director 

 of the Zoological Laboratory at Harvard University, 

 in Celebration of Twenty-five Years of Successful 

 Work for the Advancement of Zoology, from his 

 former Students, 1877-1902. Pp. xix + 513; 36 plates 

 and portrait. (New York : Holt and Co., 1903.) 



THIS stately volume is a tribute to a notable 

 personality in the history of American zoology. 

 It has been inspired by the affection and loyalty of about 

 one hundred and fifty of his former students, twenty- 

 si.x of whom contribute the memoirs which fill its 500 

 quarto pages. To their esteemed master, these 

 -students — now themselves in many cases well known 

 teachers and investigators — express their gratitude for 

 his rigorous discipline in methods of work, for his 

 critical skill, and for his stimulating sympathy. They 

 recall with pride the service that was done to science 

 by the publication of Mark's work on the maturation, 

 fecundation, and segmentation of the egg of Limax — 

 " a work that introduced into America the then new 

 cytological methods in the application of which this 

 country has since reached an elevated position. It 

 likewise introduced into zoology a proper fulness and 

 accuracy of citation and a convenient and uniform 

 method of referring from text to bibliography. It 

 marked a step forward, also, in thoroughness and de- 

 tail, and in the full recognition that, even in zoology, 

 as in physics and chemistry, method is hardly less 

 important than matter." 



The tribute of twenty-five memoirs is one to make 

 a teacher proud, especially as they exhibit many of the 

 features which have distinguished his own work. 



Seitaro Goto leads ofT with a description of a new 

 Craspedote medusa — Olindioides jormosa, n.g. et sp., 

 from Misaki, like Haeckel's Olindias in some ways, 

 yet strikingly different, e.g. in having six radial canals 

 instead of four. Along with Gonionema and Hali- 

 calyx, Olindiopsis and Olindias represent the sub- 

 family Olindiadse, which must rest meanwhile under 

 the Eucopidae among the Leptomedusae. H. S. Pratt 

 describes four new Distomes — a new genus (Ostiolum) 

 from the frog, related to Hamatotoechus of Looss, and 

 three new species of Renifer ( = Styphlodera) from the 

 mouth and air passages of common North American 

 snakes. W. A. Locy takes us into a different domain 

 in elaborating his discovery (1899) of a " new nerve " 

 in Selachians, which arises on the dorsal summit of 

 the fore-brain, before and apart from all other olfactory 

 radices, and runs to the olfactory epithelium. .\ similar 

 nerve has been recorded in Protopterus by Pinkus, and 

 in Amia by Allis ; elsewhere it has remained un- 

 detected. Jacob Reighard takes us into the open air 

 in his fascinating and most instructively careful study 

 of the breeding habits of Amia calva. The sexes differ 

 obviously in colour, but spawning is usually at night; 

 there are about three times as many males as females 

 on the spawning ground ; the male builds the nest, 

 guards and defends it ; he excites the female by biting 

 and rubbing ; he may induce two females at different 

 NO. 1834, VOL. 71] 



times to spawn in the same nest; he leads the young 

 black larvae forth, re-unites the school when it loses- 

 scent, and guards them until they begin to assume 

 orange and green hues ; he is a model of paternal care. 



Charles A. Kofoid describes an interesting Opalinid, 

 Protophrya ovicola, the least specialised member of the 

 family, which he found in the brood-sac of Littorina 

 rtidis. An interesting item is the presence of a micro- 

 nucleus, which has only been observed in one other 

 Opalinid, Anoplophrya branchiarunt. It is obvious 

 that the question of the micronucleus in Opalinids 

 should be looked into, and that this new genus should 

 be searched for in other localities. The next memoir 

 brings us back to " new-fangled " methods, for 

 C. B. Davenport compares a lot of Pectens from 

 Tampa, Florida (Pecten gibbus, var. dislocatus), with 

 another lot from San Diego, California (Pecten 

 vcntricosus). These are closely analogous species, 

 and if environmental facts are similar, the variability 

 should be the same. But in all the proportions 

 measured, the San Diego Pectens show themselves 

 from 50 per cent, to 100 per cent, more variable than 

 those of Tampa. The San Diego forms represent a 

 plastic race in a varied present environment. It seems. 

 to us that the concepts of variability and modifiability 

 must be analysed out before such statistics as those 

 offered in this memoir can be of much value in aetio- 

 logical discussion. Observed differences have to be re- 

 corded, but it is only when demonstrable modifica- 

 tional differences are subtracted from the observed 

 differences that we can draw secure conclusions as to 

 variability in the strict sense. Gertrude Crotty Daven- 

 port discusses the longitudinal division and fragmen- 

 tation of the sea-anemone Sagartia luciae, and shows 

 that numerous intermediate forms may occur while the 

 individuals are always tending by means of regenera- 

 tion in the direction of twelve stripes and forty-eight 

 mesenteries. Again, we must emphasise the desir- 

 ability of distinguishing between modificational and 

 variational divergences from the norm of the species. 



Frank W. Bancroft describes an interesting seasonal 

 modification of the compound Ascidian Botrylloides 

 gascoi; the colony died down and the zooids de- 

 generated, but with the assistance of a " yellow lobe " 

 containing no zooids recuperation was effected. Carl 

 H. Eigenmann discusses another mode of degener- 

 ation in telling the whole history of the eyes of the 

 blind Amblyopsid fishes. The foundations of the eye 

 in the embryos, which develop in the gill-cavity of the 

 adult, are normally laid, but the stages beyond the 

 foundations are coenogenetic or direct ; in fact, there is 

 a developmental degeneration corresponding to the 

 degeneration of the eye in the adult. Somewhat sur- 

 prising is H. P. Johnston's account of three fresh- 

 water Nereids — Nereis limnicola, n.sp., Lycastis 

 hawaiiensis, n.sp., and Lycastroides alticola, n.g. et 

 sp. — from indubitably fresh-w-ater habitats. The author 

 discusses the conditions which will admit of marine 

 forms becoming denizens of fresh water, and gives a 

 useful synopsis of recorded cases of fresh-water Poly- 

 chaeta. Then follows an interesting study in ethology, 

 H. R. Linville's account of the tube-formation in 

 Amphitrite ornata and Diopatra cuprea, the particular 



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