: NOTICES OF MEETINGS, 97 
clear vescicle or bladder protrudes. They breathe by means of spiracles and 
their trachea are exceedingly well developed. Their muscles are immensely 
numerous and strong, and which are capable of sustaining the caterpillar erect, 
like a dead twig. Their internal organs are very perfect, and the circulation of 
the blood is a very beautiful sight. The paper was illustrated by several well 
mounted slides representing the different organs mentioned by Mr. Hall, and 
were shown under the instruments of the various members present. 
NORTH OF ENGLAND MICROSCOPICAL SOCIETY. — The 
monthly meeting of this society was held in the Patents Room of the Literary 
and Philosophical Institution, on Wednesday evening, March 16th, Mr. John 
Brown, vice-president, in the chair. The meeting was somewhat crowded, 
many visitors—ladies and gentlemen—being present. After the minutes 
of last meeting had been read and confirmed, and other preliminary business 
completed, Mr. Mason Watson read a lengthy paper by Dr. Lionel Beale, pre- 
viously published in the ‘‘ Journal of the Royal Microscopical Society,” while 
Dr. Beale was president of that society, which seems intended as a counterpoise 
to the more advanced theories of evolution. Examples of diseased hams, taken 
from those to which Mr. John Milbourne, of this town, has recently called 
public attention, were examined, and the abundant Cystzcercz noted zz s7tu. The 
smoked hams in question were German (Westphalian), and not American pro- 
duce, This disorder can readily be seen, the “ measles,” measuring in length 
about 1-5th, and in breadth at the widest part 1-1oth of an inch; it has probably 
been known from time immemorial, and there is little doubt but that it is coeval 
with the porcine race itself. If swallowed by a suitable host, the contents of 
the cyst developes a Zaia. The occurrence of such a badly infested case 
must be rare and exceptional. The death point of these organisms is much 
below the temperature of boiling water ; hence they can only be dangerous if 
meat is insufficiently cooked. No dread of them need exist in the public mind 
if this will be properly attended t&, even were the disease a common one, 
which it certainly is not in England. Nevertheless, a too intimate acquaintance 
with Mr. Milbourne’s parasitic messmates is not at all desirable. In illustration, 
Messrs. George Harkus, Mason Watson, and J. Brown, sen., exhibited 
Trichina spiralis in human tissues. Four of these examples of German pre- 
parations were kindly sent for observation by Mr. B. J. Sutherland; Mr. M. H. 
Robson (hon secretary), Cys¢écervcz extracted from ham in question; Mr. Joseph 
Craggs some object dissected, and shewing hooklets ; Mr. T. H. Swallow, an 
intestinal parasite of pig—Strongylus paradoxus. Mr. Swallow presented the 
society with two dozen preparations of microfungi, beautifully mounted by 
himself, for which he received the thanks of the meeting. 
ROCHDALE AND WHITWORTH MICROSCOPICAL SOCIETY.— 
The usual monthly meeting of this society was held on Thursday Evening, 
March 3rd, at the chambers of the Hon. Secretary, Mr. I. Renshaw, 
L.D.S.,R.C.S., Rochdale, Mr. Councillor J. S. Hudson, one of the vice- 
presidents, in the chair. There was a very good attendance. The minutes of 
the last meeting were read and confirmed, and several new members were 
nominated. 
Mr. Joseph Astin gave an address on the Microscope and the various 
methods of illumination, with diagrams ; which was listened to with great 
attention. He described the principles of the different powers used with the 
microscope, and shewed the advantages and disadvantages of different 
combinations of lenses. He also demonstrated the effects produced by the 
various methods of transmitting light to an object, shewing how certain 
definitions may be obtained, differing in excellence and character, by using the 
different reflectors, condensers and lenses. He also shewed how to make a 
spot lens, by fixing a small disc of dead black paper on the flat surface of the 
