NOTES AND MEMORANDA. 
151 
and may then be placed under the microscope in oil of cloves. Thus 
the whole process does not take more than ten minutes. 
The sections are not only quickly but well stained, and indeed, 
as 1 have found by comparing results, for the most part better even 
than when submitted to the slow action of the carmine. 
I have, however, only treated sections of the central nerve 
system (brain and sj)inal marrow of man and animals) by this 
method, but it ought to be applicable to other structures. It is, of 
course, understood that the previous preservation and hardening of the 
preparation must be well done in order to obtain a corres23onding 
staining. For fresh preparations or for preparations in alcohol 
(which latter are generally to be avoided as much as possible with 
the central nerve system), this method does not answer ; objects colour 
best which have been hardened in chromate of potash (especially 
with the addition of a few drops of chromic acid). 
Moderate heating does not hurt the preparation ; the precipitate 
of carmine, which might be thrown down by it, may readily be 
avoided. A neutral ammoniacal solution of carmine, not too con- 
centrated, furnishes all that can be desired. 
It is not only on account of its rapidity that I now generally 
adopt this method, there is in addition the advantage that the 
preparations thus treated are coloured in a specially sharp and dis- 
tinct manner ; for example, the connective-tissue corpuscles, together 
with their long continuations into the substance of the brain, which 
insert themselves in the adventitia of the vessels, come out with a 
distinctness which it is difficult to obtain by other means.* 
A Netv Field for the Microscopist (the Flagellate Protozoa ). — In the 
April number of the ‘ Pojmlar Science Eeview,’ Mr. Saville Kent, after 
referring to the improvements which have been made by opticians, in 
this and other countries, in the construction of object-glasses, and sug- 
gesting that “ it would be a matter for congratulation if we could place 
on record side by side with this attestation to the mechanical perfec- 
tion and improvements of our magnifying instruments, evidence of an 
equivalent amount of progress achieved by microscopic workers in 
those new fields for investigation thrown open to them by the skill of 
the optician,” proceeds to give a descrij^tive outline, with illustra- 
tions, of certain of the Flagellate Protozoa — “ an extensive series of 
forms that have so far, on account of their exceedingly minute size, 
altogether evaded the notice of the microscopists of this country, but 
which at the same time most certainly surpass all previously dis- 
covered types, equally in the wonderful symmetry of their individual 
form and in that of their aggregated mode of growth, requiring for 
their satisfactory interpretation the employment of the most powerful 
and high-class magnifying powers.” 
It is impressible within the limits of a “ Note ” to give any intel- 
ligible abstract of Mr. Kent’s detailed description of some of the 
forms, for which the paper itself must be referred to. Some of them 
are described and figured in a paper read by the author before the 
Eoyal Microscopical Society, and printed in the ‘ Transactions ’ for 
January 1872. 
The close relationship which, as Mr. Kent considers, undoubtedly 
* Dr. H. Obersteiner, in ‘ Archiv f. Mikroskopische Anatomie,’ xv. 1. 
