—23— 



so recognized even by Dr. Underwood. The claims upon 

 which its specific assignment rests are not in any way sound 

 or acceptable. The assumed difference in its time of fruiting 

 and the character of its habitats dwelt upon by its author, have 

 no force, as the fruiting period of L. matricariae folium extends 

 all the way from May to October and the species has been found 

 in a great variety of situations. Even if under some conditions 

 tcncbrosum should mature spores in advance of normal 

 matricariaefolium, it would not prove anything, as the early, and 

 even abnormal fruiting of depauperate and weakly developed 

 forms is not an uncommon thing in the vegetable kingdom. But 

 such characters are not specific. Equally objectionable is the 

 adoption of species in the tenia turn group, which have nothing 

 but a difference in the size of the plant to recommend them. In 

 a climate so extraordinary as California, where vegetable produc- 

 tions common to other sections reach most unusual proportions, 

 it is not surprising that B. tematum should attain such a develop- 

 ment as characterizes the form known as Presl's silaifolium, but 

 which is merely the highest evolution of tematum. 



Absurd as the comparison may seem, it is no more unreason- 

 able to consider the boy and the man as representing two distinct 

 races than it is to consider the exhuberant California form of B. 

 . tematum as specifically distinct from its smaller companion grow- 

 ing by its side, or far away in some distant state, because the dif- 

 ferences are merely those which represent different states of de- 

 velopment under varying conditions of growth and environment. 



In the treatment of genera Mr. Gilbert has brought his work 

 into general harmony with the best workers, and he is undoubt- 

 edly right in adopting Athyrium and Nephr odium. 



The most interesting part of Mr. Gilbert's catalog is the 

 "appendix" into which he has infused so much of his own life, as 

 it were, and here his observations are especially rich in valuable 

 information and descriptive matter. Whether all of the new 

 forms described are entitled to the consideration given to them, or 

 not, is an open question, but in any case the author's judgment 

 possesses more than ordinary value and his views are entitled to 

 careful consideration. Some of the forms, however, appear to 

 rest on characters altogether too trivial, and it is especially 

 hazardous to propose new varieties of Athyrium filix-focmina 

 where there are already upward of three hundred or more named 



