208 MR. C. REID AND ELEANOR M. REID ON 
clay in which they are found. In drying they shrink, become distorted, or 
often crack and fall to pieces. It is generally necessary, however, to dry the 
lumps of clay in which the seeds are contained, or they will not fall to pieces 
when placed in water ; but this drying when tightly packed in a rigid matrix 
does comparatively little harm. After the elay has fallen to pieces in water 
the seeds should be collected while still wet and. transferred from dish to dish 
of clean water, till they are in a fit state for the next process, 
Pyritised fossils ean be preserved fairly well under water ; but in this wet 
state they can neither be studied conveniently nor photographed. If absolute 
aleohol is used for drying, the seed shrinks and is injured. We wish to 
preserve them in such a way that they ean be safely handled, turned over, 
compared side by side with recent seeds, and, if necessary, dissected. 
They must therefore be impregnated with some medium that will proteet the 
pyrite granules from the air, that will prevent the seed. from becoming 
distorted or falling to pieces, and that will leave the surface sculpture intact 
and in a state fit for photographing. The process must not be too elaborate, 
as we have to deal with thousands of seeds in a short time, 
The method we now employ is as follows :— The specimens are removed a 
few at a time from the store-bottles in which they have accumulated, and are 
washed in clean water to remove the weak formalin or salicylic acid used for 
their temporary preservation. A thin film of wax (we have used “ paraffin 
filtr. 45° Grübler & Co.”) is melted on a glass plate or slide and allowed to 
harden, The seeds or leaves are removed from the water and are placed, 
still wet, on the prepared film ; the plate is then immediately warmed from 
below to a temperature just sufficient to melt the wax. As the moisture 
evaporates from the upper surface of the specimen the wax is absorbed from 
the lower, and in a few minutes, unless the seed. is very large, the process is 
complete, the whole seed is impregnated with wax, and it is rendered so 
tough that it can easily be handled. 
When the seeds have absorbed as much wax аз they can, they are trans- 
ferred to a clean part of the plate and the superfluous wax is removed with 
warm filter-paper ; or they can be allowed to cool thoroughly and then have 
their surfaces brushed with benzine. If one surface of the seed is better 
preserved than another, that surface should be placed in contact with the 
wax, for the lower surface remains uninjured and flat even if the upper 
surface suffers slightly. 
In the determination of the species now to be recorded, we have received 
invaluable assistance from the British Museum and Kew collections, and from 
recent seeds supplied to us by Mr. James Groves. Dr. Rendle also has kindly 
examined our speeimens belonging to the genera Najas and Zannichellia, the 
discoveries in the former genus being recorded in his monograph *. Our 
* Trans, Linn. Soe. ser. 2, Bot. vol. у, (1899) p. 436. 
