neierate. 217 



case is Yamanouchi's account of the phases in the apogamy of A'cphrodiiim 

 molk. Cases in which the opposite condition exists are cited from Bower, 

 Druery and Wollaston. 



8. The imitation of characters from another generation 

 may be only partial, or both generations may be represented 

 in the same body. 



9. The exact nature of a homoeotic change is often deter- 

 mined by the nature of the nearest normal organ. 



10. A compound member may be changed in such a way 

 that some or all of the parts exhibit the plan originally 

 characteristic of the whole member. 



The writer concludes that changes that may properly be classed as 

 homoeotic have too often been called reversionary, and states that ,,the 

 antecedents of monstrous form are much more often to be sought in con- 

 temporary normal parts than in ancestral conditions". 



Most botanists will probably agree with the last remark, but it might 

 make the matter plainer if it were pointed out that homoeotic changes 

 often seem to be abnormal cases of development having little to do 

 with heredity. By this statement I mean that cell divisions have not 

 taken place according to the normal plan. In the rarer instances where 

 monstrous characters are transmitted the change is often the loss of the 

 character or characters that in some way help to guide the normal develop- 

 ment, and the plant forms in a more planless way than usual. On the 

 other hand it seems as if the term reversion might well be limited to the 

 recombination by crossing of the two or more factors necessary to produce 

 a characteristic, the elements of which have become separated through 

 mutation. Moreover it appears to the reviewer that an elementary 

 distinction may be made between homoeotic changes that are and are not 

 hereditary. 



In the concluding discussion the author presents reasons for believing 

 that homceotic phenomena are valuable to botanic theory in at least three 

 different relations; first, in estimating the true worth of teratological 

 evidence in the solution of phylogenetic problems; second, in throwing 

 hght upon the method of evolution of certain normal structures; third, in 

 furnishing data for one phase of morpho-genetics. 



E. M. East. Harvard University. 



Rosenberg, 0. Cytologische und morphologische Studien an Drosera longifoliax 

 rotundifolia. K. Sv. Vetenskaps Akad. Handl. Bd. 43, No. ii. 63 S., 

 4 Taf., 33 Text fig. Stockholm 1909. 



Nachdem Verfasser in einer Reihe kleinerer Mitteilungen auf die zur 

 Beurteilung der Bastardcytologie so wichtigen Kernstrukturen der Drosn-a 

 longifolia x rotuiulifolia hingewiesen hat, folgt nunmehr seine ausführliche 

 DarsteUung in zusammenhängender Form. Sie ist jetzt gerade besonders 

 erwünscht, da Fick in seinem letzten großen Sammelreferat die Haupt- 

 resultate des schwedischen Forschers in Frage gestellt hat. 



Dem eigentlichen Thema schickt Verfasser eine Reihe von Bemerkungen 

 über die äußere Morphologie des Z'/wf^'or-Bastards voran. Besonders zu 

 erwähnen ist dabei, daß die Einzelcharaktere nicht immer, wie von 

 floristischer Seite behauptet war, intermediär zwischen den Eltern stehen, 

 sondern zumeist auch der Mendel'schen Prävalenzregel folgen. Nur dominiert 



