ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
475 
they consist of a pigmented envelope, a silvery layer, a sheath of con- 
nective tissue, and a central body. 
c. General. 
Origin of Fauna of Celebes.* — Prof. Max Weber, in the course of 
a description of the fresh- water fishes of the Malay Archipelago, dis- 
cusses this question. He shows that Celebes has relatively very few 
fresh-water fishes, but those which are present aro Indian and not 
Australian in their characters. The poverty of the fauna cannot be 
explained by the present condition of the island, and the author believes 
that it is due to the fact that, until geologically recent times, Celebes 
consisted of a number of small islands. According to the author, the 
Mammalian fauna has also much more of an impoverished Indian than 
of an Australian character. This is true also of the other islands, and 
no sharp boundary line exists between Bali and Lombok. East of Celebes 
and Flores we come first into a distinct transition region between the 
Indian and Australian regions ; “ Wallace’s line ” does not therefore 
separate these regions. 
Bipolarity of Marine Faunas.f — Dr. A. E. Ortmann returns to a 
discussion of the contention of Pfeifer and Murray that bipolarity forms 
a very striking feature of the polar faunas. This has been denied by 
Ortmann with regard to the decapod crustaceans, by von Ihering for 
molluscs, by Breitfuss for Calcispongiae, by Herdman for tunicates, 
by D’Arcy Thompson for fishes, isopods, and amphipods, by Ludwig for 
holothurians, crinoids, and ophiuroids, by Burger for nemertines, and 
by Chun for the entire bulk of the pelagic fauna. Four cases of true 
bipolarity are admitted, which are to be explained by some theory. 
In all other cases the supposed bipolar range of a species or group 
has been connected by intermediate localities, either (a) along the 
bottom of the deep sea or in deeper strata of the tropical parts of the 
open sea, or (6) along the western shores of the continents, mostly 
connected with a descending of the respective forms into deeper water. 
“ It is possible that by these ways cases of true bipolarity may de- 
velop, provided these connections become discontinued. The writer has 
explained a true case of bipolarity ( Orangon ) by one of these ways. But, 
on the other hand, it is possible that bipolarity is to be explained by 
the Pfelfer-Murray theory in some cases by former conditions of the 
earth’s history, especially those existing at the beginning of the Tertiary 
period. Yet we do not know any concrete case of this kind, and we 
must wait for further investigation to show whether bipolarity as a relic 
of older times is realised in the geographical distribution of any marine 
animals.” 
What is Life ? J — Prof. F. E. Weiss, in his Presidential Address to 
the Manchester Microscopical Society, discusses the phenomena of life 
with special reference to the doctrine of “ vital force.” He regards 
the power of assimilation and the power of movement as the two main 
* Ann. and Mag. Nat. Hist., iii. (1899) pp. 121-36. Trans, from Zool. Ergeb. 
einer Reise in Niederland. Ost-Indien, iii. (1894). 
f Amer. Nat., xxxiii. (1899) pp. 583-91. 
X Trans. Manchester Micr. Soc., 1898, pp. 64-76. 
