CACTACEOUS GENERA. 51 
Miller, at almost the same time, in preparing a new edition of 
his Dictionary restored two more of the pre-Linnean genera, 
setting forth in that rank, Cereus, Opuntia, Peireskia and Melo- 
cactus, but to this last he assigned the Linnean synonym of 
Cactus ; perhaps wishing to conciliate, by a mere name, the pop- 
ular botanist whose system of cactaceous plants he had so 
boldly revised. 
Some twenty years or more after Miller’s restoration of the 
old genera, Necker went over the ground in his own peculiar 
fashion, reaffirming that in the Cactus of Linneus there are 
four distinct genera; and there is reason to think that this was 
an independent proposition of his own, not suggested by Miller, 
whose Gardener’s Dictionary he may not have seen. At all 
events, to three of his four proposed genera of cactaceous plants 
he assigns names so entirely new and strange, that they can not 
be identified at a glance and by name with the old genera, anda 
critical study of his diagnoses becomes necessary to the deter- 
mination of his types. 
Comparing his descriptions one with another, we ascertain 
readily that the author subscribes to an opinion, even then anti- 
quated, that only the globose and cylindric species of cacti have 
stems, and that the compressed joints of such things as the 
opuntiæ and phyllanthi are not branches but leaves; so that, 
while the globose and simple sorts are described by him as cau- 
lescent, the kinds exhibiting any manner whatever of flattened 
vegetative organs are classed as acaulescent, though the plants 
be tall and large in certain cases. But in this error we find one 
clew, and asure one, to the identification of his cactaceous genera. 
Another is given usin connection with the fruits; for he de- 
nominates a acca the smooth soft-pulpy small-seeded fruit of 
some, and as an achena that of those which as in Opuntia 
have a firm fleshiness and contain larger and bony seeds. 
These few items of Neckerian cactaceous terminology are 
enough to enable one to determine with certainty the identity 
of each of his four genera Cactus, Cirinosum, Carpophillus and 
Phyllanthus. 
Cactus, Neck. Elem. ii, 83. Of this he describes the fruit 
as being an “olive-shaped many-seeded berry.” The only Lin- 
