1907] CURRENT LITERATURE 389 



different than were the normally diverse individuals of the original species." 

 Again (p. 220), "Mutative variations commonly obey Mendel^s laws." But 

 none of the fully demonstrated mutations now known strictly obev Mendel's 



reverse 



good cause, namely, that the Mendelian inheritance of a character indicates its 

 origin by mutation. On p. 221 he says, ''The general rule must be that new 

 variant gametes conjugate with gametes of the unmutated parental type, and 

 thus have from the first the reproductive status of Mendelian crosses." This is 

 a good suggestion and should be kept in mind by students of evolution, as should 

 also his discussion of the relation betw^een the origin of characters and their effect 

 in the modification of species; but the Oenothera mutants, the best known of 



first 



Mendelian 



time of its first appearance. 



It is difficult to understand why Cook should say, "Mutation is not a period 

 but a condition/' since no one ever said or intimated that it is a period. It is 

 neither a period nor a condition, but an act or the result of that act. He says, 

 "Species have more essential evolutionary differences than mutations, though 

 mutations are at the same time more definitely different." Yet the Oenothera 

 mutants are recognized by excellent taxonomists as differing from each other 

 both as to quality and degree, just as wild species differ. ' Other statements 

 regarding the Oenotheras are not in agreement wath published facts, as for 

 instance his statement that O. LamarcUana is dominant over O. lata to the 

 extent of 85 per cent. — George H. Shull. 



The origin of angiosperms. 



proposed 



of the origin of the angiosperms, based on the recent development of knowledge 



forms 



Contrary 



to the Engler scheme, they do not regard such apetalous groups as the Piperales, 

 the Amentiferae. and the Pandanales as representing primitive angiosperms, 



but rather as reduction forms from those possessing a perianth. The primitive 

 typical angiospermous floral structure is claimed to have been an "amphispo- 

 rangiate" (substituted for the commonly used terms "bisporangiate" or "ambi- 

 sporangiate," as the proper antithesis of "monosporangiate") strobilus, in which 

 the megasporophylls are above the microsporophylls and there is a well-marked 

 perianth. Such a strobilus the authors call an "anthostrobilus," restricting 

 "flower" ("eu-anthostrobilus") to angiosperms, A "pro-anthostrobilus" is an 



form 



microspore 



form. This implies the exist ^- ^ 



with a strobilus like that of the Bennettitales, and to this hypoth 



angiosperms 



Parkin, Tohn, On the origin of angiosperms 



London 



