PHYSIOLOGY OF REPRODUCTION IN PLANTS. 



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cilia which at once germinate directly, (2) smaller Micro- 

 zoospores with four or two cilia which also germinates 

 directly, (3) still smaller Gametes with two cilia, which 

 either conjugate and form zygospores, or can be made to 

 act as parthenospores without conjugating, and (4) larger 

 fusiform Zygosphores with four cilia. Moreover, in the 

 origin of the zoospores, etc., from a cell, it is a matter of 

 conditions (chiefly nutrition and size) whether one, two, 

 four, eight, or even sixteen or thirty-two zoospores are 

 formed in a cell ; or whether eight, sixteen or thirty-two 

 micro-zoospores or gametes are formed in one cell, and 

 so on. 



One is also struck with the fact that although Klebs 

 resorts to extreme measures in some of his experiments, 

 in the majority of cases the changes of environment are 

 just such as may and do occur in nature. 



The following remarks (p. 175) seem worth careful 

 note : — 



" Es ist merkwiirdig, dass aus der Geschichte der 

 Wissenschaft so wenig gelernt wird, Schon zweimal hat 

 in der Botanik der gleiche Streit iiber den Polymorphismus 

 geherrscht, zuerst bei den Pilzen und dan bei den Bakterien. 

 Beide male ist dieser Streit aus unfruchtbaren Diskus- 

 sionen in die richtigfen, streno' wissenschaftlicken Bahnen 

 geleitet worden, als man die Reinkultur der Organismen 

 als notwendigen Ausgangspunkt ftir jede Untersuchung in 

 dieser Richtuno- verlang-te." 



While Klebs' book is a model of records of experimental 

 work, full of new points and suggestions, Mobius' " Beitrage 

 zur Lehre von der Fortpflanzung der Gewachise " is 

 rather an interesting resume of facts compiled from 

 various authors who have written on the reproduction of 

 plants. It consists of five chapters ; the first an introduc- 

 tory one dealing with the meaning of individual reproduction 

 as related to the maintenance of the species, and the signi- 

 ficance of vegetative propagation as opposed to sexual 

 reproduction proper. The point of view is elementary, 

 but a number of interesting facts are collected, and I think 

 he is quite right in insisting on the plant as an individual 



