256 ERYTHEA. 
those found on the above mentioned species. They are, 
however, far less abundant. 
In the genus Cheilanthes the Aleuripopteris division is 
distinguished by the presence of these glands. According 
to Hooker it consists of the following species: 
C. rufa, Desv. A native of Hindostan. The fronds 
are coated with a white powder. 
C. Welwitschii, Hook. A native of Angola at elevations of 
2400—3800 ft. It is covered with a bright yellow meal. 
C. argentea, Kunze. Found in Siberia, Japan, China and 
the Malayan Peninsula. Bears a white waxy powder. 
C. farinosa, Kaulf. A native of Africa, Arabia and the 
Himalayas. Bears a dense coat of pure white powder. 
C. aurantiaca, Moore. From Mexico. Is densely coated 
witha bright orange meal. 
The last species, which is the only one of this group that I 
have examined, presents a hair-structure that differs consider- 
ably from those heretofore mentioned. These glands are 
found in abundance on the lower surface of the frond, though 
sparingly observed upon the upper, but are so covered by the 
broad deltoid scales as to be rendered inconspicuous. They 
consist of four or five short cells arranged in a single row, 
the uppermost one being slightly smaller than the others. 
The indument is of a decidedly waxy nature and shows no 
signs of crystallization. It dissolves readily in alcohol or 
ether, and such a solution leaves on evaporation & yellow 
mobile oil. Itmust differ in composition from any of the 
compounds thus far discussed. 
In the genus Primula we find good examples of this kind 
of hair-structure, and in this genus also we find revealed the 
relation existing between them and similar secretory organs. 
A large number of species bear these glands though for the 
most part in comparative paucity and I think a careful study 
of the pubescence of all the forms would show all gradations 
between these peculiar structures and the typical resin secret- 
_ ing gland of which we find so good a type in P. Sinensis. 
