STEVENS: DIsCcOID GEMMAE IN LEAFY HEPATICS 372 
The development of the gemmae in Radula complanata differs 
considerably from that of R. Hedingeri as described by Goebel 
(52). He states that the gemma mother-cell divides by a number 
of longitudinal walls between which transverse walls are formed 
and that no apical cell is developed in the gemma. That this is 
not the case in R. complanata is clear from the almost invariable 
occurrence of apical cells in the young stages observed, and from 
the fact that in mature gemmae the position of the apical cell may 
generally be traced. Fic. 4, C, shows what may be considered a 
typical gemma. In this the outlines of the two-apical cells with 
their segments may be clearly traced though each of the apical 
cells has become divided into five cells. 
BOTANICAL LABORATORY, YALE UNIVERSITY. 
LITERATURE CITED 
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Evans, A. W. Hepaticae of Puerto Rico—IV. Odontolejeunea, Cyclole- 
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Evans, A.W. Vegetative reproduction in Metzgeria. Ann. Bot. 14: 271- 
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Goebel, K. Ueber epiphytische Farne und Muscineen. Ann. Jard. Buiten- 
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Nees von Esenbeck, C.G. Naturgeschichte der europaischen Lebermoose 
3: 274. Breslau, 1838. 
