THE MICROTOMIST'S VADE-MECUM

If they be replaced in water they return to the normal state .
in eight or ten hours and may be re-curarised several times.
Etherisation.-Three per cent. alcohol, or 3 per cent. ether,
may be used in a similar way. These reagents cause no heni
obstruction to the processes of cell-division, and are useful,
but their action as anesthetics is inconstant.
Indifferent media.-One per cent. salt solution, iodised         er
serum, syrup, cold water (+ 1 C.), and warm      water (35-
400 C.). The tail may be excised from the living animal and
studied for a long time in these media.                          ao
484. Methods for the Study of Cells (Flemming's methods 1).     a
-The best subject for these studies is Salamandra. The           saltso
adult offers for study the thin transparent bladder; in the
larva the gills and caudal " fin " may be studied in the living  with
state. The gills are difficult to fix in position for observation,
and are obscured by pigment. In the fin, there is always a
spot, near to the hind-limbs, that is free from pigment; and     tures
on lightly-coloured larve other such spots may be found, on iits
the ventral half of the fin and on the lateral line. On a flat-
finned larva it is possible to study these spots with a Hart- I b
nack's No. 12 imm.
The larva may be fixed in a suitable cell; or wrapped in      anIes
moist blotting-paper; or may be curarised; or the tail may        i
be excised. (It is preferable to cut through the larva close
in front of the hind-limbs).                                     tios
A favorable object for preparation is found in the gill-plates,  a1cbb
delicate lamine that are to be found attached to the gill-carti-  DapH
lages on the mouth side.                                         by M
Larvoe may be bred from adults kept in confinement, and
supplied with a vessel of water, in which they will place the    case
larvoe of their own accord. In May, gravid females may be
killed and the larve extracted. The larve must be kept in
frequently changed water, and fed every day or two. Aquatic
worms may be used for feeding them; viz. Tubifex rivulorum.       ta
1 Ibid., p. 304, et seg.                   it s

304