550 



SCIENCE. 



[N. S. Vol. V. No. 118. 



Observatory of San Salvador. Dr. Szymonowicz, 

 of the University of Cracow, has been made 

 associate professor of histology and embryology 

 in the University of Lemberg. 



DISCUSSION AND COBBESPONDENCE. 



BELATIONS OF TAKSIUS TO THE LEMURS AND 

 APES. 



Under this title Mr. Charles Earle, in your 

 issue of February 12, 1897, gives a valuable 

 contribution to our knowledge of the mutual 

 relationship of recent and fossil Lemurs and 

 discusses at the same time a proposal made by 

 myself to remove Tarsius from among the 

 Lemurs and to place it with the Primates s. str. 



Such proposal finds but scanty favor in the 

 eyes of this able paleontologist, who formulates 

 the a priori objection that "we shall be little 

 benefited by this change in the classification of 

 the Primates, as it will be exceedingly difiicult 

 to discover any characters of the skeleton by 

 which we can separate the Apes from the 

 Lemurs. ' ' 



Now, I hold that the primary object of classi- 

 fication is not to facilitate or to benefit, but to 

 establish, as closely as possible, the true posi- 

 tion which species and genera, both living and 

 fossil, occupy in the actual line of descent, 

 which is slowly but surely revealing itself to 

 the persistent and combined efforts of paleon- 

 tology, anatomy and embryology. 



At the same time, if Mr. Earle finds fault 

 with the embryologist who wishes to transfer 

 Tarsius from the Lemurs to the Apes, he is 

 fully entitled to stand by his osteological and 

 deutary characters and to fight for the current 

 classification, that is apparently more conve- 

 nient to paleontologists. He is, however, 

 bound to state the arguments of his opponent 

 fully and fairly, and this he does not do when 

 he suggests to his readers that my reason for 

 removing Tarsius from the Lemurs lies in its 

 different 'type of placenta,' nor is he quite up 

 to date in his valuation of recent placental 

 investigations when he complacently quotes 

 Mivart's and Balfour's warnings against the 

 systematic value of differences in placental ar- 

 rangements, when not accompanied by other 

 characteristic differences. 



It is, indeed, rather hard upon me, who have 

 endeavored, in the past eight years, to clear up 

 some of the confusing views that were being 

 entertained concerning placentation in general, 

 to be now pilloried by Mr. Earle as if I had 

 been making that coarse and indiscriminate use 

 of placentary characters in classification against 

 which I have been all the time loudly protest- 

 ing. Thus, for instance, I have shown that 

 the placenta of the hedgehog, the shrew and 

 the mole is in each case a structure Sui generis, 

 all these different Insectivores having placentas 

 of the discoid shape, but which reveal them- 

 selves, on close and careful examination, both in 

 their structure and in their genesis, as far more 

 different inter se than is the diffuse placenta- 

 tion of the horse from that of the Lemurs or 

 from the cotyledonary placentation of the 

 Ruminants. I have hitherto refrained from 

 proposing changes in the classification of the 

 Insectivores, because I am well aware that to 

 make these fruitful the paleontological and 

 anatomical evidence tending in the same direc- 

 tion will first have to be collected and sifted. 

 Nor would I dream of bringing Tarsius in 

 closer connection with the Apes on account of 

 the discoid placenta, for the very same reasons 

 that it is not the external shape, but the histo- 

 logical and the genetic details, which are of 

 importance in any such comparison. Still Mr. 

 Earle would make the readers of Science be- 

 lieve (see p. 258) that this is my line of argu- 

 ment! 



Referring to my paper in the Gegenbaur 

 Festschrift (1896) — the abstract of which ap- 

 peared in an October number of Science and 

 can hardly have remained unknown to Mr. 

 Earle — it will there be seen that I founded the 

 closer relationship between Tarsius and the 

 Apes on something quite diflferent, viz., on the 

 development of the embryo in a vesicle to which 

 it does not become attached by means of an 

 outgrowing allantois, but to which it is fixed 

 from the beginning by a stalk of tissue (' Haft- 

 stiel ' or ' Bauchstiel ' of the Germans), which 

 was up till lately only known as a characteristic 

 feature of the human embryo, but which Selenka 

 also discovered in monkeys (Cercocebus a. o.), 

 and which in Tarsius has now for the first time 

 revealed its entire developmental history, in- 



