June 18, 1897.] 



SCIENCE. 



957 



cada uno im hombre eucima, y muchas iguanas, 

 que son como sierpes.") G. Baue. 



Univeesity of Chicago. 



The article of Mr. Sclater in Science, May 

 14th, on the distribution of the Seals, Sirenians 

 and Cetaceans, disregards the more recent pub- 

 lications on zoogeography, especially marine 

 zoogeography. It begins with a somewhat in- 

 definite statement, that ' most of the recent 

 writers on Geographical Distribution have con- 

 fined their attention to terrestrial mammals, or, 

 at any rate, have but casually alluded to the 

 marine groups of that class.' I may be allowed 

 to state that the deficiency of our knowledge of 

 the distribution of marine animals induced me, 

 nearly two years ago, to publish a book,* which 

 is particularly intended to supply this lack. 1* 

 seems, however, that Mr. Sclater never has seen 

 this book. Mr. Sclater seems also to be unac- 

 quainted with many other writings on the same 

 subject, published since Wallace. I mention 

 only the names of A. Agassiz, G. Baur, T. N. 

 Gill, Guenther, v. Ihering, J. Murray, Neu- 

 mayr, PfeflTer, J. Walther. The natural conse- 

 quences of this neglect are most evident. 



I do not think it worth while to enter into a 

 closer examination of the theoretical views of 

 Mr. Sclater, since all these points have been dis- 

 cussed by myself and others so extensively that 

 anybody who has followed these discussions 

 will see at once that his theoretical views are 

 far from being in conformity with current the- 

 ories. I shall state, however, a few points in 

 the article referred to, by which it is proved con- 

 clusively that he did not consult most of the 

 writers quoted above. 



1. The term 'life-district' (' Lebensbezirk,' 

 ' domaine biologique ') seems to be completely 

 unknown to Mr. Sclater ; otherwise he would 

 have treated the Cetaceans separately from the 

 Seals and Sirenians. (Compare J. Walther, 

 Ortmann, Chap. 3.) 



2. The importance of the action of tempera- 

 ture-conditions has been completely overlooked 

 by him ; otherwise the effect of temperature 

 should be shown in his sea-regions. (Compare 

 Gill, Pfeffer, Ortmann, p. 37.) 



3. The distinction of autochthonts, immi- 

 *Grundziige der marinen Tiergeogaphie, Jena, 



1896. 



grants and relicts (compare Guenther, Ortmann, 

 p. 34) is unknown to Mr. Sclater ; otherwise he 

 would have assigned a different value to the 

 eared seals inhabiting the northern Pacific in 

 comparison with the other seals ; Phoca and 

 Trichechus are autochthonts, while the Otariida3 

 are immigrants. 



4. It is impossible to distinguish properly any 

 distributional regions, which depend merely on 

 a particular group of animals. The outcome 

 will always be unsatisfactory. The regions cre- 

 ated by Mr. Sclater are a striking evidence of 

 the inconveniences of this method, as I have al- 

 ready pointed out in the beginning of Chap. 4 

 (p. 44-45) of my book. I mention only one in- 

 stance : the fact that Trichechus and Phoca are 

 found in the northern parts of both the Atlantic 

 and Pacific Oceans is in no way represented in 

 Mr. Sclater' s division, although this fact is a 

 very characteristic one, and, indeed, is the rule 

 for the distribution of littoral polar animals. 

 This rule is justified and supported by the phys- 

 ical conditions of the polar seas. Nevertheless, 

 Mr. Sclater does not pay any attention to it, and 

 frames his regions with regard to exceptional 

 cases. (Compare eared seals, above, under 3.) 



5. The definition, of the Mid-Pacific Sea-re- 

 gion of Mr. Sclater is insufficient. In fact, he 

 does not give any limits, nor any characteristics 

 of this region. 



6. The relations of his Indian Sea-region to 

 his Mid-Atlantic Sea-region, due to the geolog- 

 ical conditions of former times, and still exhib- 

 ited in the distribution of the Sirenians, are not 

 referred to at all, and of course no attempt has 

 been made to explain them. (Compare Ort- 

 mann, p. 67 f.) 



7. Mr. Sclater concludes that the distribu- 

 tion of the' Otariid;o proves a connection of 

 South America with Africa by land. I should 

 suggest to him to read the papers of v. Ihering 

 on this subject (Archhelenis), before he tries to 

 bring the distribution of the eared seals in con- 

 nection with this old continent. The old Arch- 

 helenis has positively nothing to do with the 

 distribution of the sea lions ; the latter are late 

 Tertiary, while the Archhelenis was chiefly 

 Mesozoic ! The absence of any OtariidiS in the 

 middle and northern Atlantic is exclusively due 

 to temperature conditions. 



