No. 503] NOTES AND LITERATURE 



733 



It is not necessary to remind botanists of the high standing 

 of Professor Bower's numerous contributions to science. Not 

 only has such work as his great monographs on spore-producing 

 organs put him in the first rank of morphologists. but his inter- 

 pretation of the facts of comparative morphology, and his more 

 speculative papers on alternation of generations and the origin 

 of the land plants, have strongly influenced all recent theories on 

 these important questions. Professor Bower is thus peculiarly 

 fitted to treat this difficult subject, and it is with special grati- 

 tude to the author that botanists will welcome this admirable 

 presentation of the results of his many years' labors. 



It is generally admitted that the existing land flora, I e., the 

 Archegoniata^ and seed plants, are the descendants of some fresh- 

 water plants probably allied to certain green alga!; but the way 

 in which these typically aquatic organisms gave rise to forms 

 markedly terrestrial in habit is on,- of the <|iiesiions about which 

 there are very diverse opinions. Professor Bower has long con- 

 tended, and we believe that he has overwhelming evidence on his 

 side, that the characteristically terrestrial modern plant type, 

 i. e., the sporophyte or neutral generation of the ferns and 

 seed plants, is the product of the evolution of the zygote or rest- 



ds'' 1 This is the '•aiitilheiie"' theory of alternatio 



thesis. 



)gous" alternation 

 f eminent botanists 



which of late has hen: deieiuiea oy d 

 both at home and abroad, that Professor Bower defendi 



present volume. 



lessor Bower has elaborated his 

 that the sterilization of potentially 

 in the evolution of the sporophyte 

 ilarly has he made this clear in his 

 lis on the development of the spore- 



divided into three parts: (1) The Statement of the Working 

 Hypothesis, (2) Detailed Statement of Facts, (3) Conclusion. 



It has been rather the fashion of late to belittle the importance 

 of comparative morphology, as it is evident that the plant organ- 



