and Laboratory Methods. 2339 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects should be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



eu 1/ TT u J- ur I, TDi • 1. Prof. Schumann has made an extensive 



Schumann, K. Ueber die weiblichen Bluthen 



der Coniferen. Verhandlungen des Botanis- comparative study of the ovulate flowers 

 Chen Vereins der Proving Brandenburg, 44: ^f ^^e Coniferales (including Gi7lk^o\ 

 S-So, 1902. _ ... 



Little attention is given to the earlier 



developmental stages, but the later stages and the mature flowers are described 

 in great detail and many suggestive comparisons are made. Teratology is not 

 regarded as of much value in " explaining " morphological relations or estab- 

 lishing homologies. 



The more important conclusions are : that the Cupresseae are related to the 

 Taxodieae and that of living forms the genus Sequoia is nearest the point of con- 

 tact. This does not mean that Sequoia is the starting point for the Cupresseae, 

 but that this form must have been similar and related to Sequoia. This sup- 

 ports Potonie's theory that the Taxodieae appeared before the Cupresseae. 



c. J. c. 



Denke, P. Sporenentwickelung bei Selagin- Since the difficulty in securing good 

 alia. Beihefte zum Bot. Centralbl. 12: preparations has hindered accurate work 



182-IQq, pi. S, IQO2. , ,- r ^ , • 11 



on the finer structures of Selaginella, 

 any suggestions as to methods of treatment are welcome. The usual Flemming's 

 solution and also that of Hof causes a collapse of protoplasmic structures, and 

 material so fixed does not stain well. Cones treated with boiling water for 4 to 

 5 minutes and then gradually dehydrated in alcohol also proved unsatisfactory. 

 After trying these and several other fixing agents, Dr. Denke recommends the 

 following method : 



Absolute alcohol .... 2 parts. 



Glacial acetic acid . . . . l part. 



This solution is allowed to act for 26 hours, after which the material is placed 

 in 50 per cent, and then in 70 per cent, alcohol, 2 hours each ; 70 per cent, 12 

 hours; 80 per cent, and 95 per cent., 24 hours each; absolute alcohol, 7 hours; 

 clear in chloroform (10 to 24 hours?); in paraffin bath at least 8 days. Sections 

 were cut 5 to 7.5/< thick and stained in Haidenhain's iron alum heematoxylin 

 with or without a counterstaining with Congo red. Clove oil was used for 

 clearing. 



The following are some of Dr. Denke's conclusions : The cauline sporangia 

 originate from epidermal cells and underlying tissue. In the microsporangium 

 a considerable number of spore mother-cells fail to undergo the tetrad division. 

 Such cells lose protoplasmic contents and function like tapetal cells. Micro- 

 sporangia and megasporangia develop alike up to the spore mother-cell stage, 

 and in phylogeny probably represent a common structure. In both microspore 



