130 DR. H. CRUGER ON THE FECUNDATION OF ORCHIDS 
which they gnaw off with great industry, and for which there is 
a continual contest. The same substance is also very attractive 
to other insects, such as cockroaches, &c. 
This same substance, ©. e. some cellular tissue which these 
humble-bees gnaw off, exists also in the hypochil of Coryanthes ma- 
crantha. They are seen in great numbers disputing with each other 
for a place on the edge of the hypochil. Partly by this contest, 
partly perhaps intoxicated by the matter they are indulging in, 
they tumble down into the * bucket," half-full of a fluid secreted 
by organs situated at the base of the column. They then crawl 
along in the water towards the anterior side of the bucket, where 
there is a passage for them between the opening of this and the 
column. If one is early on the look-out, as these Hymenopters 
are early risers, one can see in every flower how fecundation is 
performed. The humble-bee, in forcing its way out of its 
involuntary bath, has to exert itself considerably, as the mouth of 
the epichil and the face of the column fit together exactly, and are 
very stiff and elastic. The first bee, then, which is immersed will 
have the gland of the pollen-mass glued to its back. The insect 
then generally gets through the passage, and comes out with this 
peculiar appendage, to return nearly immediately to its feast, 
when it is generally precipitated a second time into the bucket, 
passing out through the same opening, and so inserting the 
pollen-masses into the stigma while it forces its way out, and 
thereby impregnating either the same or some other flower. I 
have often seen this; and sometimes there are so many of these 
humble-bees assembled that there is a continual procession of 
them through the passage specified. 
I have not seen the fecundation of Stanhopea; it is visited by 
the same insect, and I have caught it with the pollen-mass of the 
plant on its back, but I do not see how it can insert the same 
into the stigma. The insect visits this flower again for the 
purpose of gnawing off some substance from the labellum ; but the 
same is so far removed from the stigma, that it could hardly, in the 
fully-opened flower, perform the act of impregnation except in very 
rare cases and accidentally. I may say that Stanhopea grandiflora 
very rarely bears seeds. E 
The disposition of Stanhopea, and partly of Catasetum, where 
there is no stigmatic liquid substance secreted at the exterior of 
the column, and where consequently the pollinia have to be 
inserted into the stigmatic transverse cleft, is repeated in Gongora 
maculata, L, (figs. 4, 5, 6, magnified). This plant often bears fruit. 
