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THURSDAY, OCTOBER 5, 1911. 



A ZOOLOGICAL TRIBUTE. 

 Festschrift zum Sechzigsten Geburtstag Richard 

 Hertwigs (Miinchen) geboren den 23. September, 

 1850, zu Fricdrich, i.H. Erster Band, "Arbeiten aus 

 dem Gebiet der Zellenlehre and Protozoenkunde." 

 Pp. v + 674 + 49 plates. Price no marks. Zweiter 

 Band, "Arbeiten Morphologischen, Biologischen und 

 Deszendenztheoretischen Inhalts." Pp. iii + 624 + 30 

 plates. Price 70 marks. Dritter Band, " Experi- 

 mented Arbeiten." Pp. iii + 3oS + 20 plates. Price 

 50 marks. (Jena : Gustav Fischer, 1910.) 



THE three volumes before us represent one of the 

 most remarkable tributes ever paid to a professor 

 of zoology. We refer not merely to their size and 

 weight, which have unfortunately hindered us from re- 

 viewing them more promptly, but to their high 

 standard of workmanship and to the cordiality with 

 which the various authors recognise indebtedness to 

 their master for inspiration and instruction, for precept 

 and example. It is true, of course, that those who 

 have joined in this " Festschrift " to their highly 

 esteemed teacher are now strongly marked individuali- 

 ties, ploughing their own furrows ; yet it would be 

 less than fair not to see that the diversity of contri- 

 butions is correlated with the diversity of gifts in 

 Richard Hertwig himself. For he has worked along 

 many lines of zoology, and always with signal success 

 — with a carefulness, thoroughness, and thoughtful- 

 ness which we should not presume to praise were they 

 not reflected so clearly in the volumes which it is our 

 ttisiness to-day to review. He has dealt with Protozoa 

 and Metazoa, with morphology and physiology, with 

 the most minute intricacies of the cell, with the big 

 questions of sex and reproduction, and with the 

 .general problems of evolution. The congratulations of 

 Naturf. to Richard Hertwig, as one of the big inter- 

 national educationists in zoology of recent years, may 

 be, through the reviewer's fault, a little belated, but 

 they are none the less sincere. We wish for him many 

 years of pleasant work, judiciously mingled with as 

 much holiday as he can enjoy. 



But how are we to review three enormous volumes 

 with 1600 pages and a hundred plates? Perhaps the 

 |Dlost useful way is the objective one of giving a rapid 

 ■fventory of the treasures of this great Festschrift. 



W. T. Howard leads off with an account of a 

 peculiar kind of nuclear budding which occurs in the 

 "depressed" cells of some tumours. It represents a 

 (reversion on the part of these cells to a primitive type 

 of division common among certain Protozoa (such as 

 iPodophrya, according to Hertwig), and the author 

 jalso suggests that the degeneration and extrusion of 

 [nuclear buds followed by mitosis of the mother nucleus 

 lis, in principle, comparable to the maturation division 

 lof egg cells. M. Popoff describes in various cells of 

 [Muscidae what Hertwig called the formation of 

 .chromidia — the extrusion of chromatin from the 

 [nucleus into the cytoplasm. This colonisation of the 

 Cytoplasm by nucleoplasm seems to bear a relation to 

 (the functioning of the cell; thus the chromidia may be 

 NO. 2l88, VOL. 87] 



distributed along lines of diffusion currents. The 

 author points out that what have been described as 

 mitochondria, chondriomites, chondriokonts, pseudo- 

 chromosomes, ergastoplasm, and so on, are simply 

 phases of chromidia. Prof. Vlad. Ruzicka has studied 

 in Bacterium nitri the relations of chromatin and of 

 plastin to the life of the cell, and finds that these two. 

 substances tend to be distributed respectively in areas- 

 of active and of reduced metabolism. In a paper with 

 very striking illustrations, Th. Moroff describes what 

 goes on inside the large Radiolarian Thalassicolla, the 

 nucleus of which can be seen easily with the naked 

 eye. The vegetative and reproductive phases are con- 

 trasted, and an account is given of the formation of 

 isospores and anisospores. The author discusses such 

 points as the significance of nucleoli, which are inter- 

 preted as forms of chromidia. 



C. Clifford Dobell gives an account of his study of 

 an interesting blood parasite, Hasmocystidium, dis- 

 covered by Castellani and YVilley in a Ceylon Gecko. 

 He describes the schizogony and the formation of 

 gametocytes, and contrasts the genus with the malarial 

 organism, Plasmodium, to which it is closely akin. 

 Hubert Erhard shows, in reference to the cells of the 

 bile-duct in the snail, and of the epididymis in the 

 white mouse, that the " trophospongia " of Holmgren 

 is really a chromidial apparatus of nuclear origin. In 

 regard to the epididymis he brings forward strong 

 evidence that the secretion is due to the activity of the 

 chromidia in the cytoplasm. In the next study Julius 

 Schaxel describes the oogenesis of the well-known 

 jellyfish Pelagia. He lays emphasis on the interesting 

 give and take between nucleus and cytoplasm ; from 

 nutritive material supplied by the cvtoplasm the 

 nucleus forms chromatin, part of which is emitted 

 from the nucleus into the cytoplasm to form physio- 

 logically important " kineto-chromidia." The history 

 of the chromosomes in the larval salamander is the 

 subject of a study by Karl Camillo Schneider — a kind 

 of study which is difficult for those who have not a 

 clue to the labyrinth of the nucleus. We may, how- 

 ever, point out that according to the author each 

 chromosome of the nucleus in the prophase before divi- 

 sion is bivalent, being composed of two " elementary 

 structures" or "Mites," which are spirally coiled! 

 In following the history of these spirals Schneider has 

 found strong corroboration of Boveri's theory of the 

 individuality of the chromosomes. In the next paper 

 Paul Buchner gives a redescription — more penetrating 

 than ever — of the spermatogenesis and oogenesis, the 

 maturation and fertilisation in Sagitta. 



E. A. Minchin describes Malpighiclla refringens, a 

 new amoeboid parasite which he found in the mal- 

 pighian tubes of the rat-flea (Ceratophyllus fasciatus), 

 in which he was studying the transmission of Trypano- 

 soma lewisi. It occurs principally in two forms — an 

 amoeboid form with a single nucleus, and an encysted 

 form with four nuclei. In the next paper we are 

 brought back again to chromidia, for Alexander 

 Issakowitsch describes these on the marginal gland 

 cells of Porpita, and shows that they play an essential 

 part in the production of mucus. Then follows an 

 interesting study by Rh. Erdmann, dealing with 



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