412 Mr. Bowman on the Parasitical Connection 
siderably. A longitudinal section of one of these cells may not - 
inaptly be compared to the folds within the helix of the human 
ear; but its usual form may be seen in the magnified perpendi- 
cular section, Tas. XXIII. Fig. 7; and its cross section in Fig.8. 
10. & 11. The compound microscope shows every part of its sur- 
face to be lined with innumerable oval transparent glands or pa- . 
pillze, some sitting, but for the most part raised on pedicels of va- 
rious lengths, and all pointing towards the centre of the cavity. 
These glands are so minute as to be barely visible with the 
lowest magnifier of the compound microscope. ‘Their situation 
may be seen in Fig. 10. & 11; and their shape, very highly 
magnified, in Fig. 12. They are marked by four longitudinal 
depressions, which indicate as many septa or valves within, the 
intermediate spaces being hollow (see d. and e. of Fig. 12.); but I 
have not been able to ascertain whether the apex of the gland, 
or the pedicel, be perforated. They have a very beautiful ap- 
pearance under the compound microscope, either in a trans- 
verse section of the cell, or when the lining of the cell is viewed 
as an opake object. On account of their extremely delicate 
texture, they soon shrivel up as the section dries. 
_ Though satisfied, from the elaborate structure of these secret 
chambers, that they were destined to perform some important 
office, and that they must, some way or other, have an exterior 
communication, it was not till after repeated observations and 
many tedious and unavailing efforts, that I had the good fortune 
to discover it. Ifthe longitudinal section ofthe leaf and one of 
its cells (T'as. XXIII. Fig.7.), or the more highly magnified part 
of it (Fig. 9.), be attentively examined, a very narrow interstitial 
opening or passage may be traced from a. inwards, between the 
incurved lower edge of the leaf d, and the underside of the leaf- 
stalk e, and leading into the inclosed wider space within, b 
This inner space (a cross section only of which can be shown 
in 
aloa NM 
€ mi p REPE. a rm e aae enna ac ius 
