431 
number of the trichomes of the Arthrospira held together by a 
common jelly. 
The diameter of the trichome is from 2.5-3 4. It is regularly 
twisted into a rather lax spiral, the distance between the turns 
being 16-18 m, and the width of the turn about 6 yw. Caduceus 
forms are not uncommon. The cells of the trichome vary from 
4-5 » in length; the cell divisions in vigorous trichomes are in- 
distinct with few granules and with the cell contents light bluish 
green by transmitted light. In the majority of the cells large 
vacuoles are present. 
This form is decidedly smaller than either A. Jenneri or A. 
Platensis and with a laxer spiral. From A. mintaza it differs both 
in habitat and habit, and in the fact that the extremities are not 
at all capitate. As the species appears to be new, the writer de- 
Sires to dedicate it to M. Maurice Gomont, of Paris, as a token of 
his esteem and respect. 
The writer wishes also to express his deep obligation to Dr. 
Bornet and M. Gomont for assistance in determining the above- 
mentioned forms, as well as others, without which no certainty 
Would have been possible. 
Personal Nomenclature in the Myxomycetes. 
By O. F. Cook. 
As has been said, there are two ways of naming plants, ac- 
cording to the system of priority, or according to the personal 
System, which is no system at all. The alleged object of both 
methods is to secure uniformity of nomenclature, and opinion upon 
their relative merits depends on whether uniformity with the past 
is looked upon as more important than uniformity with the future. 
That the personal system does not always secure uniformity even 
With the immediate past is evidenced by two recent books, both 
Purporting to be monographs of the same group of organisms. 
They are based, practically, on the same collections and are pub- 
lished Only two years apart. Massee’s “ Monograph of the Myxogas- 
“res” recognizes 41 genera. Lister’s “ Mycetozoa”’ describes 38, but 
13 of these are different from those of Massee. Massee has 430 
Species, of which nearly one-third are not recognized as valid by 
Lister, while another third have their names changed, so that of 
