The Distribution of the Hepaticce. 
no part in supplying the leaf-trace. The stem and leaf-structures 
seem rather out of relation, and when the structure of other species 
of Acrostichum is considered it would seem that the leaf-trace 
must have undergone considerable independent evolution. It is 
possible also that the cauline vascular system has been reduced 
from a more complex type. Concerning the possible causes of 
such phenomena we are unable to say much in the present state 
of our knowledge. 
ON THE DISTRIBUTION OF THE HEPATICzE, 
AND ITS SIGNIFICANCE. 
By Douglas Houghton Campbell. 
(Professor of Botany at Stanford University , California). 
HE many important researches on palaeozoic and early mesozoic 
fossils made during the past few years have very much altered 
the conclusions formerly accepted as to the nature of many fossil 
plants. While no doubt many of these new conclusions will be 
accepted, there is no question that some of the recent ones are 
premature, and are scarcely warranted by the evidence at hand ; so 
that it will perhaps be just as well to pause before throwing over 
without question the results of work done in other lines than those 
of palaeontology. 
In his admirable survey of the present position of palaeozoic 
botany (Progressus Rei Botanicae : June, 1906) Dr. D. H. Scott, in 
commenting on the great scarcity of unmistakable bryophytic 
remains in palaeozoic formations, while admitting that too much 
stress should not be laid upon negative evidence, nevertheless is 
evidently inclined to the opinion that the evidence at hand indicates 
that the Hepaticae are not improbably of comparatively late origin. 
