common matter were operative in the production of the first 

 organized Beings of this planet. " The earth brought forth 

 grass and herb yielding seed after his kind, and the tree 

 yielding fruit whose seed is in itself." " The waters brought 

 forth abundantly the moving creature that hath life;" and 

 " the earth brought forth the living creature after his kind, 

 cattle, and creeping thing, and beast of the earth." But of 

 our own species it is written, " God created man after his 

 own image, in the image of God created he him ; male and 

 female created he them." And " God said unto them, Be 

 fruitful, and multiply and replenish the earth." (Gen. i. 

 27 and 28.) 



Since that first fiat went forth, the propagation of the 

 species of plants, animals and mankind has been left to the 

 operation of certain natural secondary causes, which we 

 sum up as the ' act of generation.' 



Botanists and physiologists have observed and progres- 

 sively analysed the phenomena until they have reduced 

 them to a great degree of simplicity, the essential condi- 

 tions being the same, or closely similar, in both realms of 

 organic nature. 



With regard to the animal kingdom, the generation of 

 which here concerns us, the essential conditions of the act 

 appear to be a nucleated cell, and the product of a nucle- 

 ated cell, with the combination of the two : the nucleated 

 cell is the c germinal vesicle/ and is the essential part of the 

 ovum ; the other nucleated cell is the ( sperm-cell/ and its 

 product is the spermatozoon. 



It is essential to the development of the germ that the 

 ovum receive the matter of the spermatozoon : it is then said 

 to be impregnated. 



The phenomena that thence ensue are essentially the 

 same up to a certain point in all animals, and consist in 

 the formation of a germ- cell (PI. I. fig. 4, c), and its propa- 

 gation of a numerous offspring (fig. 10) at the cost of the 

 germ-yelk (fig. 4, a), by a series of reiterated spontaneous 



