72 



hairy covering. The growth of one sporophyte proceeded at a 

 more rapid rate than that of the other resulting in their unequal 

 size (shown in figure 2). Unequal growth of the setae starting at 

 a very early stage caused them to become slightly separated 

 and probably accounts for the fact that they have not taken 

 part in the twinning. 



It is to be hoped that more teratological specimens such as 

 the particularly interesting cases figured by Schimper (1861) 

 may be discovered at earlier stages in development in order 

 that the true nature of those in which the setae are nearly or 

 completely fused may be known. 



The writer is indebted to Professor Armand Renier, Chief 

 of the Mine Service of Belgium, and to certain other Belgian 

 scientists, whose kind assistance made possible many collecting 

 trips in that country. 



Literature cited 



Gyorffy, I. 1934. Doppelte Mooskapseln aus Frankrelch. Rev. Bryologique et 



Lichenologique 7: 117-121. 

 , 1936 Polytrichum Abnormitaten aus der Hohen-Tatra. Acta Biologica 



4: 123-132. Schimper, W. Ph. 1861. 



Observations sur Quelques Cas de Teratologic Bryologique. Bull. Bot. Soc. 



France 8: 351-353. 



Washington University 

 Saint Louis, Mo. 



