64 
contracted in the middle, especially those near the points of 
the cones. The leaves are not more than six inches long, 
the cones are about four inches long, and very regularly 
ovate. Mr. Hartweg found it in ravines near Apulco grow- 
ing fifty feet high. 
101. CUPRESSUS thurifera (Schlechtendahl) ; 
Found near Anganguco and Tlalpuxahua, forming a tree 
50 to 60 feet high ; 
102. JUNIPERUS tetragona (Schlechtendahl) ; 
a beautiful shrub, with quadrangular branches and small 
glaucous fruit, making a bush from four to five feet high, on 
the road from Real del Monte to Chico; 
103. JUNIPERUS flaccida (Schlechtendahl) ; 
a beautiful small tree from 15 to 20 feet high, with 
weeping branches and glaucous fruit as large as a hazel 
nut, from the neighbourhood of Regla; and 
104. JUNIPERUS mexicana (Schiede) ; 
an upright shrub or small tree, with large greenish, irre- 
gularly oblong fruit, producing a resin like Sandarach in the 
Real del Monte mountains; have also been received by the 
Society, and their seeds are in the course of distribution to 
the Fellows. 
Notes upon the Plants that produce some of the fetid gum-resins of the 
Materia Medica. 
There is so much uncertainty in the source from which 
the foetid gum resins are obtained, the origin of Galbanum 
and Sagapenum being unknown, that of Asafetida disputed, 
and that of Ammoniacum dependent upon evidence which 
requires confirmation, that any new information upon this 
subject is of interest. Through the kindness of the Honour- 
able W. F. Strangways, I have been put in possession of 
some new evidence collected in Persia by Sir John McNiell, 
and it is so satisfactory as to deserve to be made known. 
105. Ammoniacum is certainly produced, as Professor 
Don states, by Dorema ammoniacum, it having been found 
B Re 
