58 AMERICAN FERN JOURNAL 
and at home. The wealth of illustrations will serve to 
make identification of common ferns an easy task. 
(Two of the plates are here reproduced through the 
courtesy of Mr. Hopkins.) 
BR. Cy 
Tue PRoTHALLIA or OpHIOGLOssuUM AND BoTRYCHIUM 
The prothallia of ordinary ferns are so well known and 
so easily obtained that the ordinary stages of prothallial 
growth are matters of elementary instruction in botany. 
The prothallia of Botrychium and Ophioglossum, however, 
are very uncommon and even yet only a few kinds have 
been found, altogether five species in Ophioglossum, 
and three or four in Botrychium. Of these five are fairly 
well known, the others only incompletely. When it is 
considered that there isa total of over fifty species in these 
two genera distributed all over the earth it seems strange 
that so little is known about them. 
Prof. D. H. Campbell, of Leland Stanford University, 
has given special study to these two genera, and has 
made extensive trips to the tropics to secure material of 
them. In Java, he secured good material of Ophio- 
glossum moluccanum and O. pendulum, as well as of other 
ferns of interest. He had as long ago as 1892 begun 
his study of O. pendulum, and about the same time of 
Botrychium virginianum. In the intervening time other 
writers have found and studied Botrychium virginianum 
more completely (Jeffrey), Ophioglossum vulgatum and 
B. Lunaria (Bruchman). These five species are really 
the only ones which are at all thoroughly known, and 
there are many points about these still to be cleared up. 
The other species on which a small amount of work has 
been done are as follows: B. matricariaefolium and B. 
simplex, and O. intermedium. The list has been given 
thus completely because our knowledge of the prothallia 
