630 Bray: THE Tissues OF SOME OF THE 
The guard-cell apparatus seems to consist of five or six pairs of 
auxiliary cells in addition to the usual guard-cells proper, giving 
a flexible arched covering to the large air-chamber beneath. 
Fic. 8. Surface view of stomata like that shown in f 7, after removing wre 
cuticular layer. yg, yg, the guard-cells; 2, a, etc., the five pairs of auxiliary cells; 
the epidermal cells proper. 
The cells of the assimilation zone are very large and arranged 
palisade-wise for several layers, becoming, then, spherical, thick- 
walled and much pitted storage-cells. 
5. Euphorbia antisyphilitica. Thisisa leafless Euphorbia with 
the habit of an Eguisetum. It occurs in very great abundance 
amongst the rocky débris of the hills and mountain slopes of the 
Great Bend region, especially in the Terlingua district, and is 
plentiful in some spots as far down the river as the mouth of the 
Pecos. 
In general, the plant shows a moderately thick-walled epidermis 
thickly coated with wax (/. 9, ep, wa), which is clear and marked 
by minute longitudinal furrows on younger stems, but which be- 
