COOK—NOMENCLATURE OF SAPOTE AND SAPODILLA. 283 
nothing is gained by admitting Achras and other Linnean substitutes 
for pre-Linnean names like Sapota and then allowing these same 
pre-Linnean names to be brought back into the system because they 
happened to be misapplied by some of the early post-Linnean 
writers. 
If the Linnezan genus Achras had not been based on the same 
type, the placing of Plumier’s name Sapota as a synonym would not 
stand in the way of restoration by a later author who used it in the 
original application, but it is certainly not in the interest of nomen- 
clatorial stability to revive discarded pre-Linnzan names that have 
been replaced by direct substitutes, as in the case of Sapota and 
Achras. It is a rule of botanical nomenclature that the substitution 
of a new name does not alter the type of a genus. Still less should 
the type be changed by the casual use of a name for species not con- 
generic with the original type. Pre-Linnzan genera used~by post- 
Linnean authors should not be treated as having been adopted under 
the binomial system unless the pre-Linnzan type was included. Ap- 
plication of this rule to the present case requires us to seek a post- 
Linnean generic name for the sapote. 
LUCUMA AND VITELLARIA NOT APPLICABLE TO THE SAPOTE. 
The name usually given to the sapote in post-Linnzan literature is 
Incuma mammosa, but this generic assignment seems not to be cor- 
rect. The genus Lucuma was established by Molina in 1782 on a 
Chilian tree not closely related to the sapote, and the tendency of 
recent writers has been in the direction of separating the sapote from 
Lucuma. Radlkofer, Pierre, Engler, and Urban are in agreement 
in this respect, though differing in their applications of generic names. 
Radlkofer proposed to revive the name of Gaertner’s problematical 
genus Vitellaria and apply it to the sapote, but other writers have 
not followed this suggestion. As long as the type of Vitellaria remains 
unidentified the application of the name can not be determined. 
Many other genera have been segregated from Lucuma or are treated 
as synonyms, but none of them appears to have been based on the 
sapote or its closer relatives. Thus the sapote appears to have had 
no generic name of its own until 1890, when Pierre established a 
new genus, Calospermum, with Achras mammosa L. as the type 
species. 
CALOSPERMUM AND CALOCARPUM AS HOMONYMS. 
The name Calospermum was changed by Pierre to Calocarpum in 
1897. The reason for this substitution was not stated, but may be 
found in the fact that Pfeiffer’s nomenclator credits Rafinesque with 
having given the name Calospermum to a genus of alge in 1814. 
Yet the name Calocarpum is open to even more serious objection, 
