20 
New Researches on the 
[January, 
same direction, is very far from meeting the demands of 
Science, We are no nearer than we were half a century 
ago to the decomposition of any element, or to the meta- 
morphosis of one into another. In one sense even we are 
further off. Considering the greatly improved means of 
research which chemists now have at their disposal, and the 
number of well qualified savants who have attacked this 
problem from different sides, we feel that the probability of 
a solution is lessened. We can only hope that some untried 
path, of which the world has no conception, may some day 
lead to the desired end. 
III. NEW RESEARCHES ON THE FECUNDATION 
OF ANIMALS. 
FECUNDATION AND SUBSTITUTION. 
* HE remarkable advances made recently in the study of 
the fecundation of animals are known to all biolo- 
gists. A recent monograph by Prof. E. van Beneden, 
summarised in the “ Naturforscher,” developes a new appre- 
hension of the essence of this process, and compels us to 
recur to this important question. 
The modern views on the process of fecundation, as they 
are now universally accepted, date back to the researches of 
Biitschli. This savant was the first to show that in the 
yolk of the fecundated ovum of Rhabdites dolichura there 
appear two nuclei which soon move towards the centre of 
the yolk, and coalesce to form the nucleus of the first 
embryonic cell. Two years afterwards, in 1874, this disco- 
very was confirmed by the researches of Auerbach. A little 
later Biitschli discovered, further, that in place of the ger- 
minal vesicle there appears a fibrillary spindle (the spindle 
of direction) like that which is formed in the cell-nucleus in 
the moment of segmentation. This spindle takes part in 
the formation of the polar vesicles, which, as it is known, 
are expelled from the ovum. 
