GENESIS OF MAN. 31 



The sperm-cells of mammals possess a no less marked similarity, 

 They are exceedingly small as compared with the germ-cells, and 

 possess long filiform caudal appendages. The chorion is wanting. 

 Their form may be divided into head, body and tail, but between 

 no two of these parts can there be said to exist any clear line of 

 separation. The head contains the nucleus surrounded by proto- 

 plasm or cell-substance, which is carried backward in gradually 

 diminished quantity, forming the remaining portions. It was not 

 until the year 1873 that it was discovered that these important or- 

 ganisms, like the female ova, were simple cells. This discovery is 

 in great part due to Prof. Haeckel's own investigations. 



We may now consider the immediate consequences of the union 

 of the sperm-cell with the germ-cell. The spermatozoon penetrates 

 the many times larger ovum, making its entrance through minute 

 pores in the chorion, and mingling at once with the germinative 

 matter of the cell. A remarkable change takes place. Two per- 

 fect cells with opposite sexual polarities have been drawn together 

 by their inherent affinities. They have met and their substances 

 have commingled. They literally blend into one individual. But 

 that individual is no longer a cell. The sperm-cell has lost its in- 

 dividuality and wholly disappeared. The nucleus of the germ- 

 cell has likewise entirely vanished. The entire interior of the 

 original cell has become a homogeneous mass of protoplasm, no 

 longer possessing any traces of organization. Only the chorion 

 remains to determine its original form. It is a case of retrogres- 

 sion [Ri'ickbildung), of reversion to the lowest type of existence. 

 The human being who, as represented in sperm-cell and germ-cell, 

 stands on the plane of the amoeba and the infusorium, has gone 

 back, on the union of these cells, to that of the money. As if 

 nature was not satisfied that any form of life should begin with the 

 cell, the second stage of existence, but required absolutely that 

 every being, no matter how high might be its destiny, should go 

 to the very foot of the scale and climb the entire distance, in order 

 that it might pass through every form that has belonged to its 

 whole line of ancestors. 



From another point of view, this union and literal blending of 

 the male and female principles is not only of the highest intellectual 

 interest, but is calculated to awaken the most lively aesthetic senti- 

 ments. Nothing more poetic or romantic has ever been presented 



