195 
Botanical Notes. 
Comparative Anatomy of the Filz-like Hair-covering of Leaf- 
organs. Emily L. Gregory, Bryn Mawr College, Pa. (In- 
augural dissertation for obtaining the degree of Doctor of 
Philosophy presented before the Philosophical Faculty of the 
University of Ziirich, 1886, p. 42, illustrated.) 
The thickening of the upper cells of hairs as compared with 
the basal ‘cells and those of the epidermis beneath them, together 
with a certain form of stoma, noticed on leaves growing in a 
very moist atmosphere, suggested the probability of a connec- 
tion between the hair-covering and the ability of leaves to take 
up moisture in a liquid state from the atmosphere. The investi- 
gations recorded in this paper seem to show that the leaf-hairs 
may contribute actively to the supply of water in the plant, as 
well as to prevent the escape of that taken up by the root-hairs. 
Recent investigations by others tend to substantiate this conclu- 
sion. Lists of plants are given which are grouped according to 
the anatomical and physiological characters of the hair-covering 
of their leaves. Of those in which the basal-cells of the hairs are 
living and best fitted to absorb water, the following native or 
naturalized plants are worthy of mention :—-Zusstlago Farfara, 
Inula Helenium, Artemisia ludoviciana, Antennaria plantaginea, 
Potentilla anserina, Anaphalis margaritacea and Artemisia vul- 
garis. Ofthose studied in which this function is doubtful the 
following are mentioned :—Populus alba, Tilia alba and T. 
pubescens, Cynoglossum officinale, Dryas Drummondit and 
Ledum latifolium. 
Experimental tests were applied in order to determine the 
relative power of absorption of the basal cells of hairs as com- 
pared with the epidermal cells; wilted leaves were lightly 
brushed with water so as to moisten the hairy coating, but not 
the epidermis, and the recovery of turgescence timed. The 
plasmolytic condition of the basal cells of hairs was found to be 
greater than that of the epidermal cells. The most decisive re- 
sults were obtained with plants of arid regions, Helicrysum petio- 
/atum from the Cape of Good Hope and Salvia argentea from 
Southern Europe. In the case of A/fredia cernua an interesting — 
peculiarity was noted ; it was found that the hairs on the veins — 
