1900-1.] Mr E. H. A. Marshall on Hair in the Eqwidce. 379 
this description to hairs in general. My own observations have 
shown it to be very generally applicable to the shoulder and side 
hairs in the Equidse, but this cannot be said for the hairs of the 
mane, sections through which are commonly circular throughout 
the entire length of the hair, the exceptions being, so far as I have 
seen, certain very long and fine mane hairs of horses and the mane 
hairs of the mountain zebra. These are elliptical. The flattening, 
as is well known, is related closely to the tendency the hair has to 
•curl. Thus, in animals with stiff upright manes we should expect 
to find a circular hair section. 
Like Nathusius, whose investigations were almost entirely upon 
horse and ass hairs, I have employed hairs from the shoulder 
region. By simply mounting such hairs in balsam, many of the 
•characters can be quite well made out. But I have also employed 
mane hairs, which from their greater value for taxonomic purposes 
mid the much greater ease in cutting them into transverse sections, 
■are more useful for purposes of comparison. Cutting sections 
through hairs is always a matter of some difficulty, and not the 
least part of it is to contrive that the sections shall be transverse. 
Dr Hepburn has been kind enough to show me the apparatus he 
has invented and employed for keeping the hairs stretched out 
during embedding. It consists of two small metal boxes open at 
their ends and made to fit into each other. The hairs are stretched 
across the open end of one of the boxes, which on being fitted into 
the other one, retains the hairs in position. The whole apparatus 
can then be embedded in paraffin, and the paraffin block containing 
the stretched hairs can be cut out of the metal box (since the ends 
are open) after solidifying. I have employed this apparatus for 
the shorter hairs, but for longer hairs it is just as easy to embed in 
■an ordinary paper box, keeping the hairs stretched across by 
fastening their ends in holes in the paper. The hairs were cleared 
in xylol or turpentine before being embedded. I have found 
paraffin of a melting point of 58° C. the best for embedding in. 
The sections were cut with a Cambridge rocking microtome at a 
thickness of lOyu,, cleared in xylol and mounted in Canada balsam. 
The material employed has been largely provided by Professor 
Ewart, either from animals in his stud at Penycuik or from skins 
in his possession ; but I have been able to confirm some of my 
