176 GEOLOGY. 
PARTIAL DEVELOPMENT or EGGS WITHOUT FERTILIZATION.— 
Hensen has observed that the eggs of rabbits, unimpregnated and 
within closed cysts, developed themselves into polynucleated pro- 
toplasmatic masses and fibres. Kupffer also noticed that 
Ascidia there arises in the egg before impregnation a peripheral 
layer of cells which, later on, after impregnation, becomes the ex — 
ternal covering of the animal. More recently, as we learn from 
the “ Quarterly Journal of Microscopy”, (Ellacher has observed the 
remarkable fact that even in warm blooded vertebrata the first act 
of embryonic development, namely, segmentation, may take place 
independently of impregnation. : 
= 
Frora anp Fauna or tae Azores.—The most striking fact 
brought out by Godman’s ‘ Natural History of the Azores, oF 
Western Islands,” is the wonderful amount of similarity between 
the productions of these remote islands and those of Europe; 
from eighty to ninety per cent. of the birds, butterflies, beetles 
and ,plants being absolutely identical with common European 
species, while from one to four per cent. only are American. 
This is the more remarkable when we turn to physical maps for s 
information and find that both the oceanic and aërial currents A 
from the westward, so that we should naturally expect the Amer- 
ican element of the fauna and flora to be much better represt™” 
The difficulty, however, is to a great extent cleared up by Mt 
Godman’s observation that the Azores lie in a region of storms 
from all points of the compass ; and that every year these storm 
bring numbers of birds from Europe, and no doubt also num ) 
of insects, although these are not so easily observed. wW 
thus account for the enormous preponderance of European sp" 
and this, taken in conjunction with the entire absence of ! 
genous Mammalia and Reptiles, causes our author to PE 
theory of a common continental extension uniting these o 
Europe as the origin of their fauna and flora. Had this been 
_ and taking into consideration the vast time implied by the 
_ of a thousand miles of country to the depth of fifteen 
feet, we should certainly have found the productions of the 
to be far more endemic and peculiar than those of M 
the Canaries, instead of far less so. ae 
The most curious and difficult problem is presented by T 
istence of a considerable number of wingless beetles of € 
culiar to the Atlantic islands (Azores, Madeira, Canaries). 
