THEORY OF SEX — ITS NATURE AND ORIGIN. I 27 



(3.) A third reason why the proljlem of the origin of male 

 and female has been so much shirked, why naturalists have 

 beaten so much about the bush in seeking to solve it, is that in 

 ordinary life, for various reasons, mainly false, it is customary 

 to mark off the reproductive and sexual functions as facts 

 altogether pe7' se. Modesty defeats itself in pruriency, and 

 good taste runs to the extreme of putting a premium upon 

 ignorance. Now this reflects itself in biology. Reproduction 

 and sex have been fenced off as facts by themselves ; they have 

 been disassociated from the general physiology of the individual 

 and the species. Hence the origin of sex has been involved 

 in special mystery and difficulty, because it has not been 

 recognised that the variation which first gave rise to the 

 difference between male and female, must have been a varia- 

 tion only accenting in degree what might be traced universally. 



§ 4. N'atu7'e of Sex as seen in its Oj^gin among Plants. 

 — In tracing the origin of sex, we would wish to guard 

 against any impression of having consciously or unconsciously 

 arranged our facts in the light of the theory we hold. Hence 

 we prefer to follow some accessible account, taken essentially 

 from the morphological point of view. We shall follow Prof. 

 Vines in his article Reproduction— Vegetable., in the Encyclopcedia 

 Britannica, at each stage, however, endeavouring to interpret 

 the facts, physiologically, in the light of protoplasmic processes. 



(i.) The simple alga, Protococcus — which, in the widest sense of that 

 term, every one knows in some form or other, on tree-stems, in pools, 

 wells, and the like — reproduces itself in a simple fashion. The cell divides 

 into a number of equal units or spores ; these are set free, are mobile for a 

 while, eventually come to rest, and develop to the normal size. A hint, 

 however, of the beginning of a difference is seen when the cell occasionally 

 divides into a larger number of smaller spores. These, however, show no 

 difference in history. They settle down, and develop just like their more 

 richly-dowered neighbours. We find here the occurrence of units of smaller 

 size, that is to say, less predominantly anabolic, but still these are able to 

 develop independently. 



(2.) In a higher alga, Ulothrix — one of the series known as Confervce — 

 both large and small reproductive cells are developed. The large ones 

 develop always of themselves, and so may the smaller forms. But the 

 smaller forms may also unite in pairs, and then start a new plant from the 

 double capital thus attained. When one of the smaller cells develops by 

 itself, the result, in some cases at least, is a weakly plant. They have what 

 Prof. Vines calls an "imperfect sexuality," for while they are in part 

 dependent upon union with other cells, they are not wholly so. They are 

 anabolic enough, we may say, sometimes to develop independently, but 

 often they are individually too katabolic for anything but weak independent 

 development. In uniting, however, in mutual nutrition, they are strong. 



