766 On the Development of the Stomata, etc. (October, © 
division of one of the others. Occasionally stomata are also 
found on the underground stems for some distance below ground. . 
In all such cases they are without the accessory cells, and the 
guard-cells are of the ordinary shape, and not compressed. 
As far as I have been able to ascertain, the form of stomata ~ 
found in Indian corn is general among the grasses, but usually 
the stoma proper is neither so narrow nor so much constricted ; 
this is, however, not so in all cases. 
In the examination of both these plants, it is mecessary to 
examine the youngest attainable growth, as the stomata are fully 
formed very early. In Tradescantia, I took the bases of the 
youngest leaves that I could procure, those that scarcely showed 
at all without removing the outer leaves, and taking the youngest 
parts of this, placed it under the microscope without attempting 
to remove the epidermis. The leaf at this stage of its growth is 
so thin as to be almost transparent, and by careful focussing, I 
was able, with little difficulty, to get the youngest forms. In corn 
I made an oblique section of the stem quite low down, and taking 
out the bundle of young leaves from within the stem, treated 
them the same way as in Tradescantia. Only by doing this is it 
possible to get at the young forms, since any leaf which is firm 
enough to allow the epidermis to be removed, would show only 
forms complete, or nearly so. 
In the Tradescantia the stomata are confined to the lower sur 
face of the leaves, the upper surface being absolutely without 
them, while in Indian corn, although they are much more numer- 
ous on the Jower than on the upper side, they are still found to 
some extent on the latter. 
On first examining the younger forms of the Indian corn sto- 
mata, I thought that the accessory cells were formed from the 
mother-cell by internal division; but after having examined the 
formation of the accessory cells of Tradescantia, I was struck by 
the similarity of the two, and on reéxamination of the Indian 
corn, I was convinced that they were cut out of the adjoining 
epidermal cells, and were in all respects identical with those 
around the stomata of Tradescantia. 
