14 W. J. BAUMGARTNER. 



.somes described, and the interpretation that has been put on 

 them, they make the suggestion (p. 591) that many of the 

 chromosome forms are artefacts, " dass es sich bei manchen von 

 ihnen um Kunstproduckte handeln mochte, wie sie durch die 

 Conservirung hervorgerufen werden." 



From the two excellent reviews of the literature referred to 

 above it will be seen that all attempts at an explanation of the 

 various shapes aimed at proving that there were two longitudinal 

 splits of the chromosomes and hence two equational divisions, or 

 a longitudinal split and a transverse split, hence an equational and 

 a reductional division. Reduction is the question around which 

 the whole discussion centers. 



Montgomery's (25) observations on the salamanders show 

 that in these forms there is a side-to-side union of the chromo- 

 somes in synapsis. The Schreiners (27) have observed the same 

 fact in some of the lower fishes. If this proves true for the ver- 

 tebrates in general, and if Farmer and Moore are correct in inter- 

 preting one of the longitudinal splits in plants as the line of union 

 of two chromosomes, then the contradiction between Korschelt 

 and Heider's eumitotic and pseudomitotic division is removed. 

 The question as to which is the equation and which is reduction 

 division has largely lost its importance, not because they have 

 lost their significance as Wilcox (34) put forth, but because it is 

 shown that there is an equation and a reduction division whatever 

 may be the appearance of the chromosome in the prophase of 

 the first maturation division (see Montgomery (26)). 



I wish now, after having referred to the above general reviews, 

 to discuss several papers more in detail because of their interest 

 from my special view point. 



Griffin's (12) work is taken by Korschelt and Heider (14) as a 

 typical case of their "post- reductional" divisions. He gives care- 

 ful descriptions of minute details. In the prophase he figures 

 fourteen different shapes in the text and describes them as " rings, 

 crosses, double rods, and apparently homogeneous rods variously 

 coiled and bent." On page 607 he says : " Despite the varied 

 forms presented during the prophase the chromosomes of the 

 equatorial plate exhibit considerable uniformity. Hence the 

 various prophase forms must in some manner be convertible into 



