774 The American Naturalist. [September, 
and L. superbum stand together in the July meadows as the 
type of their order and of the Hypogyne. Their high order 
of development and their blooming season has a significant 
bearing on our problem. The aquatic Pontederiaces and the 
ephemeral Commelinacee, both few in species, and the odd 
genera Aletris and Xyris, are of mid-summer. With Smilax 
comes the nearly-related Dioscorea. Markedly conspicuous 
' mid-summer Hypogyne, rather intermediate between Liliaceæ 
. and Cyperacez, are the widespread and aberrant, glumaceous 
types, Juncaces. But even these are less highly specialized 
than the two great orders Cyperacee and Graminace:e, com- 
prising over half of all our Monocotyls. The Graminacee are 
unquestionably the more highly specialized, and as distinctly 
aberrant, among Liliiflore, as are the Lilia typical. Their 
period of greatest predominance extends from mid-July well 
into October. In Cyperaces it is curious that over half the 
order, the great genus Carex, attains full perfection in May; 
while the type-genus Cyperus belongs to August and Sept- 
ember, most other genera to mid-summer, and a few to June. 
But mark especially: all the summer and fall Cyperacez, 
save a very few, are hermaphrodite, while Carex is entirely 
unisexual. The significance of this will come up later. 
The review of Monocotyls closes with the Epigynous Lilii- 
flore, a small group compared with the Hypogyne, but 
peculiarly interesting. Of the generalized-normal order Amaryl- 
lidaceee we have only one wide-spread species, the little 
Hypoxis, of early summer. Iris comes in the spring and 
Sisyrinchium a little later, both rather specialized genera. 
Finally, the crowning glory of its class is the highly specialized 
order Orchidaceæ. Late in May come the earliest forms,— 
Orchis, , Arethusa, and Corallorhiza. In early June :—Pogonia, 
Liparis, Calopogon, Listera, several green Habenarias, and the 
splendid genus Cypripedium. The succession of species in this 
genus is instructive :—Earliest, in late May, comes the little 
white C. candidum ; a little later the low stemless type with 
its large complicated flower, C. acaule; still later the small- 
flowered but tall-growing C. parviflorum; later yet, the large 
cousin of the last, C. pubescens; and latest, late in June, most 
