VOLUME LIV 



NUMBER 3 



THE 



Botanical Gazette 



SEPTEMBER 1912 



the life history of aneura pinguis 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 1 59 



Grace L Clapp 



(WITH PLATES IX-XIl) 



Historical 



In his classical study of liverworts, Leitgeb (19) has given a 

 comparative treatment of the genus Aneura. Stages of develop- 

 ment chosen from several species picture the life history of the 

 genus rather than that of any one species from spore to spore. 

 Hofmeister (13) earlier described the apical cell and sex organs of 

 Aneura pinguis, and Kny (15) worked out in an elaborate scheme 

 the segmentation of its apical cell. Le Clerc du Sablon (18), 

 Goebel (10-12), Campbell (3), and Cavers (4) have since added 



facts, but gaps have been left in the continuous development, 

 chiefly in the embryogeny and in the growth of the sporeling. 



Material 



Material of Aneura pinguis was collected by Dr. Land at 



Xalapa, Mexico, in the autumns of 1906, 1908, and 1910. The 



region around Chicago has offered abundant supply for field study. 



The plants were killed in the field in Flemming's fluid (weaker), in 



alcohol (50 per cent) and formalin, and in chrom-acetic acid without 



osmic acid. Following the close series of alcohols in dehydration, 



the material imbedded in paraffin was cut in sections 3-10 p thick. 



Safranin and anilin blue, Haidenhain's iron-hematoxylin with and 



without Magdala red, and Flemming's triple stain were used for 



177 



