157 
eral Mexican species, including one of New Mexico (E. horri- 
dus), which Dr. Gray had previously named Elaterium ? Coul- 
tert). Bentham & Hooker, in their Genera Plantarum (1867), 
tefer Megarrhiza to Echinocystis as a subgenus, and include also 
Naudin’s Echinopepon, which they knew only from his description. 
Dr. Torrey had in 1861 prepared a report’ upon the Pacific 
Coast plants of the Wilkes Expedition, among which were speci- 
mens of Megarrhiza, but when in 1873, after his death, the report 
was taken in hand by Dr. Gray for publication, it was found that 
Dr. Torrey “had left the article on this genus unwritten, and 
apparently had not determined either upon the number of species 
Or upon the distinctness of his proposed genus.” Dr. Gray, 
therefore, as the easiest way of meeting the difficulty, adopted the 
conclusion of Naudin and Bentham & Hooker, and included under 
Naudin’s one species (Z. fabacea) all the known western forms. 
_This was the condition of things when it became necessary 
for me to revise the species for the “Botany of California.” A 
study of all the considerable material and notes that were avail- 
able left me in no doubt regarding the generic distinctness of the 
western species, and I had no hesitation in adopting Dr. Torrey’s 
name for the genus, defining five species from the Pacific Coast. 
In 1877 the peculiar method of germination in Megarrhiza 
was described by Dr. Gray in the Journal of Science. Inthe same 
year Cogniaux, of Brussells, discussed the group in his “‘ Diagnoses 
de Cucurbitacées Nouvelles,” though uninformed respecting the 
recent work upon it. He followed Bentham & Hooker in includ- 
ing the whole in one genus, which he divided into two sections— 
Euechinocystis of two species (one eastern and one western), and 
Echinopepon, as defined by Naudin, to which he added other 
Mexican and South American species. It was only with much 
hesitation (‘nous avons hesité longtemps”), however, that he 
assented to the reduction of the last genus. In his later revision 
of the order (1881) he has found reason for modifying his con- 
clusions so far as to divide the genus into three sections—LEuechino- 
eystis for the one eastern species, Marah for the five species of 
Megarrhiza of the Botany of California, and Echinopepon to in- 
clude sixteen southern species. 
The decision to which American botanists should come re- 
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