the Embryos and Seedlings of the Cactaceae. 463 
of its embryos or seedlings has been published, that given 
by Goebel, cited above. In the embryos of both A. fissu- 
ratinn and A. prismaticum which I have studied, the hypo- 
cotyls are very succulent and somewhat elongated. The 
cotyledons are hemispherical, merging without visible boundary 
into the hypocotyl, rather broad, so that the groove between 
them is much longer than in any of the Mamillariae I have 
studied (compare Fig. 49 c and 50 b with 47 c and 48 c), and 
in this respect, as well as in the way in which they merge 
without break into the hypocotyl, they are much more like 
E. horizon talon ins (Fig. 38) than like any Mamillaria. The 
rather abrupt ending of the groove and its slight broadening 
there is also characteristic of both Anhalonium and E. horizon- 
talonius , and it is not marked in any M amillaria I have 
seen. This fact however can hardly mean relationship, but 
merely coincidence, for the two vegetative points to the 
tubercle show a close relationship with Mamillaria and an 
origin from Thelocactus. I think it most likely that Anha- 
lonium has come off from Thelocactus independently of, but 
near to, Mamillaria. 
The development of the epicotyl in both species is remark- 
able. The first tubercles are long and slender (Fig. 49^ and 
50 ^ ; also Goebel, Plate II, Fig. 7), and bear several feathered 
spines at their tips. The whole appearance of these tubercles 
strongly recalls that of the adult tubercles of Leuchtenbergia , 
and it is very difficult indeed to resist the belief that they are in 
some way connected. But the markedly pointed cotyledons 
of Leuchtenbergia in contrast with the very low rounded 
ones in Anhalonium makes any direct relationship well-nigh 
impossible, and we must attribute the resemblance of the 
tubercles to parallelism and not to any direct connexion. On 
the other hand, following the hint given by the cotyledons, 
it is not at all difficult to imagine the pronounced tubercles 
of a form like E. horizontalonms (Fig. 38 d) growing out into 
the tubercles of Anhalonium . As the epicotyl becomes older 
the new tubercles become broader and flatter, and pass gradu- 
ally over into the well-known angular tubercles of the adults. 
