52 



cells which secrete them and may act apart from such cells," the 

 author continues: "Yeast cells on the other hand do not per- 

 ceptibly secrete their alcoholic ferments in like manner but give 

 rise to them in such minute quantities that they cannot be iden- 

 tified." Reynolds Green's paper of 1898, on "The alcohol- 

 producing enzyme of yeast," described in detail experiments 

 which led him to the conclusion that, contrary to his own state- 

 ment of 1897, active yeast cells do secrete an enzyme, which is 

 capable of causing fermentation in sugar solutions under condi- 

 tions which prevent the activity of living yeast. This enzyme 

 was called by Buchner Zymase, not "xymase," as in the text 

 under review. 



The specific name of the bracken fern is aguilina, not 

 acquilina (pp. vii and 109). The "leaf of a fern is the entire 

 aerial part" (p. 114) only in some species, not in others as, e. g., 

 Drynaria, Polystichum varium and the tree ferns generally, not to 

 attempt a complete list. On the same page, and in one para- 

 graph, the foliage organs of Pteris are referred to, in one sentence 

 as leaves, in another sentence as stems. On page 117 occurs the 

 persistent error that starch is manufactured by photosynthesis. 

 The branching of the fern rhizome is considered (p. 119) to occur 

 only "now and then," and to be "only an exceptional method of 

 reproduction." On page 121 we are told that at the time of spore 

 formation "the margins of the mature leaves . . . turn under," 

 etc. On page 124 the foot of the young embryo is said to be 

 derived from two of the cells of the quadrant. The origin of the 

 root is not given. 



To state (p. 107) that the nervous response of the higher 

 plants "is limited to protoplasmic irritability," is to ignore all 

 such common motor reactions as those of Mimosa, Dionaea, 

 Drosera, and others, and the numerous and universal movements 

 of tropistic response. On p. 29, we note "Brewer's" yeast. 

 Throughout, proteid and protein seem to be used interchange- 

 ably. Yeast (p. 33) is stated to be, "as regards nutrition at 

 least," intermediate between plants and animals. Spore form- 

 ation in bacteria is stated to be "not a method of reproduction." 



One of the commonest errors in English in scientific writing in 



