ON NEW FACTS LATELY PRESENTED IN OPPO- 
SITION TO THE HYPOTHESIS OF BIPOLARITY 
OF MARINE FAUNAS. 
ARNOLD E. ORTMANN. 
BIPOLARITY in the distribution of marine animals, indicated 
by Théel as early as 1886, has been proposed as a theory by 
G. Pfeffer.1_ Later, J. Murray? accepted the theory and tried to 
support it by a careful collection of facts. From the beginning 
the present writer, chiefly relying on the investigation of the 
distribution of decapod crustaceans, vigorously objected to the 
theory, and expressed his views as early as 1894 and 1895, 
contending that the cases introduced by Pfeffer were not cor- 
rect. In 1896, after the publication of Murray’s paper, the 
writer published an article* dealing with the subject more 
closely, and arrived at the conclusion that bipolarity does not 
exist as a general law of distribution among the decapod 
crustaceans, and that it seems very improbable that such a 
law may prevail among other groups of animals. 
J. Murray disregarded these objections, and on different 
occasions ® continued advancing bipolarity as a distributional 
fact, which called forth repeated objections on the part of the 
writer. Since then (1897) other zodlogists have taken part in 
ersuch iber die erdgeschichtliche Entwicklung der jetzigen Verbreitungs- 
verhdaltnisse unserer Thierwelt, p. 38. Hamburg, 1891. 
2 Trans. Roy. Soc. Edinburgh, vol. xxxviii (1896), No. 2, p. 494- 
3 Jenaische Denkschr., Bd. viii (1894), p. 76, and Grundsziige der marinen Thier 
geographie, p. 52. (This latter book was issued in December, 1895, but bears the 
date 1896 on the title-page.) 
4 Zool. Jahrb., api Bd. ix (1896), pp. 571 #7 
5 Nature, vol. lv (1897), No. 1430, p. so and in 7he Geograph. Journ., vol. xii 
(1898), N 
8 Zool. A Syst., Bd. x (1897), p- 217, and Science, vol. viii (1898), p. 516. 
Pfeffer (Zool. Anzeig., Bd. xx, September, 1897) has referred to the first of these 
objections; but since he does not discuss the matter at all, and only doubts the 
ability of the writer to investigate this topic, it is better not to consider this note. 
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