272 the president's address. 



of budding, or geneagenesis, than to true parthenogenesis.* From 

 the researches of Pringsheim and De Bary, nevertheless, we are 

 justified in still holding parthenogenesis to* be a phenomenon ex- 

 hibited in plant-life as well as in animal, for the disease of salmon 

 (Saprolegnia ferax) and most of its allies present parthenogenetic 

 forms. Pringsheim states distinctly that ''the successive genera- 

 tions both of Saprolegniaferax and Achlya polyandra, produced by 

 cultivation, become smaller, and the. number of male filaments 

 diminishes in each succeeding generation until they finally cease to 

 be formed, and thus the monoecious forms become replaced by 

 purely female ones," which shows that under cultivation the forma- 

 tion of male organs diminishes and ultimately ceases, and then 

 parthenogenesis comes into operation. Chara crinita is represented 

 in some localities by the female form only, yet bears an enormous 

 number of spores capable of germination, f 



Germination, or increase by budding, is such a common pheno- 

 menon in plants that it is scarcely necessary to allude to it ; the 

 same process in animals being much more rare. A familiar example 

 may be found in the common Hydra. Quatrefages says, " I agree 

 with Owen, Steenstrup, Van Beneden, Carus, &c, in considering 

 the agamic reproduction of aphis to be due to a process of internal 

 budding. It has been proved by the researches of these naturalists 

 that the reproductive bodies which are developed during summer in 

 the wingless aphides are simple deciduous buds. "J And again the 

 same author, " There is but one mode of sexual reproduction, whilst 

 there are several forms of agamic generation which are found equally 

 in the two kingdoms. In certain plants we find, besides the true 

 bud — the bulb — a genuine bud, like that we have referred to, but 

 which becomes detached from the parents, and is developed by 

 itself as though it had been a seed. We ourselves have found this 

 deciduous bud in Synhydra, an animal closely akin to Coryne. The 

 lower Alga3 are propagated by spontaneous division, and the in- 

 fusoria are in no way behind them in this respect. Trembley pro- 

 pagated Hydra by artificial cuttings, perhaps more extensively than 



* Strassburger, " Polyembryonie," Jena, 1878. In this connection 

 may also be consulted " Farlow on Pteris cretica," in " Quart. Journ. Micro. 

 Sci.," xiv. (1874), p. 267. 



t Sachs' " Text Book," p. 902. See also on Parthenogenesis, Siebold on 

 True Parthenogenesis in Moths and Bees, translated by W. S. Dallas. Prof. 

 Owen on Parthenogenesis, Braun Uber Parthenogenesis bei Pflanzen, Berlin, 

 1857. 



X u Metamorphoses," p. 168, note. 



