Origin of Sex. 311 



cells, there are intermediate sorts of union in which a number of cells, 

 more than two, enter into combination before division either fission or 

 segmentation can take place. First, in asexual organisms where usu- 

 ally growth by the absorption of nutritive matter proceeds till a certain 

 point is reached, when the body splits in two, it sometimes happens 

 that the preliminary growth is attained by several cells eating each 

 other, or clubbing together and fusing their protoplasm. Some Algae 

 and several forms of simple animals have been observed to do this. 

 Many of the simple Algae produce spores by a preliminary union of the 

 protoplasm of two individuals which appear to be attracted to each 

 other, and to come into close contact ; after which the cell walls be- 

 tween the two are obliterated and the contents of the cells fuse together. 

 After a time this mixed protoplasm granulates into spores, and the cell 

 bursts and sets them free. This is, to all intents and purposes, sexual 

 reproduction. That is, the two protoplasms are of complemental polar- 

 ity, and so they attract. In the cases in which three or four spores get 

 together before they have sufficient capital to divide, the presumption 

 is that some of them are neutral or indifferent in some way are of in- 

 complete or defective organization. They recall the indifference of the 

 spores of Protomyxa when first discharged from the cyst, which soon 

 after turns to attraction. There is certainly no difference in principle 

 in the conjugation of cells, be they many or few. But great differenti- 

 ations arise in the machinery of this conjugation, and in the morphol- 

 ogy of the cells directly concerned in it. The earliest conjugations are 

 between cells of similar form and appearance, while those concerned in 

 the reproduction of higher organisms are more or less dissimilar in form 

 and size, and between the two extremes there is a regular gradation 

 without any sudden break. In Algae the series of gradations is stated 

 by Sachs to be complete " between the conjugation of similar cells and 

 the fertilization of oospores by antherozoids. " 



Tu un i mals as well as vegetables the difference between the forms of 

 the sexual organs and the immediate cells themselves has become pro- 

 nounced. The difference in appearance, size and behavior between the 

 spermatozoon and ovum has been sufficiently described above, and it 

 has been sufficiently shown to be in the nature of the differentiation of 

 accessory qualities and facilities, the essential qualities of sex not being 

 subjected to differentiation by anything that could happen to it on earth, 

 since it is founded in the ultimate motions of matter. Geddes and 

 Thou son adopting Rolfs views have seized upon these Secondary char- 

 acteristics, and appear to regard them as essential. Thus the female 

 cell, ovum, is characterized as well nourished, satisfied and quiescent ; 

 and the female is said to he correspondingly in a nourishing condition 

 physically. The male cell is on the other hand sui<J to be starved, 



