WITH NOTES ON THE EPPING FOREST SPECIES. 25
under the microscope on the table. A short account followed of
the manner in which the plasmodium ultimately assumes the
form of the sporangia, which resulted in the production of the
innumerable spores, thus completing the cycle of changes through
which the organism passes.
If any of your readers wish for a fuller account than your
space will admit, I may add that the Trustees of the British
Museum have issued a Guide to the British Mycetozoa exhibited in the
Department of Botany (price 3d.) which gives in the introduction
a more detailed sketch of this remarkable life-history with
illustrations.1
For those who are disposed to take up the study of these
beautiful organisms, I offer, at your suggestion, Mr. Editor,
a few directions regarding their collection and preservation.
In the first place it 'must be borne in mind that although
Mycetozoa abound in the Forest they are for the most part
minute and fragile, and require patient and careful searching
for, and, further, that their investigation can only be con-
ducted by the aid of a good, though not necessarily expensive
microscope. (Messrs. R. & J. Beck, 68 Cornhill, supply as
cheap and efficient an instrument as any maker I know.)
A 2-inch objective is a convenient power for gaining a general
idea of the object, and 1/6 inch objective is necessary for examining
the minute detail; these two powers are sufficient for the
determination of species, but for thorough investigation a 1/10th in.
water immersion, or a Zeiss's 1/15th in. is often useful.
In collecting, we use a square basket with a lid ; into this
leaves may be placed one over another without fear of injury
(as the curved surfaces of holly and most other leaves protect the
sporangia from being crushed), while you have plenty of room
to pack away sticks and rotten wood on which many species are
found. When the sporangia are not mature, be careful to
surround them with plenty of damp leaves, and on reaching home
lay the unripe specimens on a wet plate under a bell jar for 24
hours, or longer if necessary. Many rare forms in our public
herbaria have been rendered almost worthless by being allowed
to dry before reaching maturity. It may prevent waste of time
for the searcher to remember that the species growing on leaves
are generally found on the upper layer of those that are wet
and rotten, among which the plasmodium has been feeding ; it
1 Students should also consult Mr. Lister's larger Monograph of the Mycetozoa, with 78
plates and 51 woodcuts (price 15s.) also published by the Museum authorities, and obtainable
at Cromwell Road.—Ed.