THE MORPHOLOGY OF THE TH ALEXIS AND CUPULES 
OF BLASIA PUSILLA. 
MARGUERITE B. ROHRET. 
HISTORICAL. 
First mention of the genus Blasia was made by Micheli Nov. 
PI. Gen. 1729. Linnaeus recognized the genus and added the 
specific name pusilla in his Species Plantarum 1753 p. 1138. In 
1759 Schmidel wrote his ‘ 1 Dissertatio de Blasia.’’ Hooker 1816 
called the plant J ungermaunia blasia but as this classification 
is much too broad it is not used today. Gottsche 8 1828 published 
an account of the germination of the spores of Blasia pusilla. 
Later Gronland published his investigations of spore germina- 
tion in the leafy Jungermanniae, including Blasia in his discus- 
sion. In 1833, Nees von Esenbeek 12 made some investigations 
on vegetative propagation and erroneously stated that the bud- 
receptacles (cupules) of Blasia are closed when young and open 
at the top at a later period. An incorrect figure of Hedwig’s 
had probably given rise to this error. Hofmeister 9 included in 
his work on The Higher Crytogamia, a short sketch of vegeta- 
tive reproduction in Blasia, but some of his views are probably 
as faulty as those of Nees von Esenbeek. 12 
The most comprehensive study of Blasia pusilla was the classi- 
cal work of Leitgeb 10 1874. His work was mainly on the gen- 
eral characters of the thallus, and on gemma formation. The 
development of the gemmae was treated in detail, following 
closely the work previously done by Hofmeister. He also fig- 
ured a few antheridia, several archegonia, and stages in the 
development of the sporophyte. Further work on the species 
was not reported until 1913 when W. E. Woodburn published 
his paper on the spermatogenesis of Blasia pusilla. 
THE THALLUS. 
Blasia pusilla is a temperate zone liverwort of wide distribu- 
tion. The species belongs to the Jungermanniales, which includes 
about 135 genera and over 3,500 species. This order of Hepatics 
is divided into the two sections Jungermanniaeeae Acrogynae and 
J ungerm an ni aceae Anacrogynae. In the first group the apical 
