ON THE STRUCTURE OF CRUCIFEROUS FLOWERS. 9 
organs with the elements of the corolla they have always been 
looked upon as constituting a single calyx.* This is exactly the 
case in the andreeceum of the Cruciferæ. We shall see too 
shortly whence this inequality of height proceeds. It is sufficient 
for our present purpose to say that in numerous cases it is almost 
. null, and in others it does not exist at all, particularly in the 
species that are normally or accidentally tetrandrous. 
It would appear that the remarks of M. Krause on the em- 
bryogeny of this familyt are at variance with the explanation 
given above. According to this observer, the four geminate 
stamens first appear in the bud under the form of four little 
papille placed before the petals. The researches of M. Duchartre 
seem to confirm this observation. 
We have ourselves opened several young buds of Sinapidendron 
Bourgeaei, and in this species at least we find that the excrescences 
which are to form the petals, are placed by no means opposite the 
middle of the young filaments, which would constitute a real oppo- 
sition, but obliquely and opposite their margin. The younger the 
buds we opened, the nearer was the approach, not to a real oppo- - 
sition, but on the contrary to an alternation. Moreover, we had 
the good fortune to meet with a bud in which the andreceum had 
returned to the quaternary type. In this case the alternation was - 
complete, and as if to confirm our opinion of the reality of this 
alternation when the stamens are double, there was a slight cleft — . 
in the middle of one of the nascent filaments, indicative of the ae 
gemination which usually takes place. 2 
THE DISK AND GLANDS. 
The receptacle of the Cruciferæ is enlarged more or less in dif- — 
ferent species, and forms a sort of glanduliferous disk, (Zpipode, — 
Richard,) usually of a deep green, of a fleshy consistence, and. 
often very apparent. 2 
| The glands, exserted upon this disk, have either been not 
o In the genus Krameria the folioles of the calyx eur. = 
f Einige Bemerk. neber Bie der Fumar. d Crucif. Flora od bot. Zeit. 4 
