THE NORTHERN MICROSCOPIST. 
to 
~I 
NO 
Section of stem of nutmeg tree, Palate of cuttle fish, Circulation of blood in 
frog’s foot, Head of bee, Pulex irritans, and various diatoms. Mr. Thomas 
Collinge, the Borough analyst, exhibited a number of slides showing the 
adulteration of food-stuffs. 
The Vicar, the Rev. Canon Maclure, had consented to open the exhibition, 
and between three and four o’clock, in the presence of a large assembly, the 
ceremony was performed, 
PARASITES AND MESSMATES. 
On Wednesday evening a lecture entitled as above was given in the Lecture 
Hall, Acker-street, to persons attending the exhibition, by Mr. C. L. Jackson, 
F.R.M.S., F.L.S., president of the Bolton Microscopical Society. There was 
a large attendance, Dr. J. H. Worrall, J.P., of Bacup, presiding, in the 
absence of Mr, Alderman Baron, the Mayor of Rochdale. The lecture was 
illustrated with the oxy-hydrogen lime light lantern, the objects being delineated 
as seen under the microscope. 
At the outset the lecturer pointed out the fact that parasites pervade all 
portions of the animal and vegetable kingdom, and are both external and 
internal. Parasites have often parasites living upon them so that (as he after- 
wards quoted parodying Swift)— 
The big fleas have little fleas upon their backs to bite ’em, 
The little fleas have lesser fleas and so ad infinitum. 
Speaking of parasites as not being altogether the worse than useless creatures 
we supposed them, he said that the most disgusting parasite was the human 
parasite—the man who preys upon others, converting all God’s gifts to a use 
and purpose for which He never intended them. (Applause.) Some animal 
parasites merely attached themselves to another body for a home, or to obtain 
locomotion. Others attached themselves either partially or temporarily for 
food, or entered the body and took up their abode there. Dealing with 
external parasites, the first parasite figured was the harvest-bug, so common in 
the South of England. The next was the itch parasite, which the microscope 
had done good service in detecting, and so enabled us to deal with the loath- 
some disease more effectually. The tick infesting sheep was shown, and then 
the parasite attacking the linnet, the lecturer remarking that birds are perhaps 
more subject to the attacks of external parasites than animals. The parasite of 
the ostrich, the one attacking the ‘‘ house fly ” (under which general name there 
were a good many species), and one attacking a species of beetle, having been 
figured, the lecturer came to the common flea, of whom he spoke, in spite of 
his other feelings towards him, as a jolly little fellow, who eludes one’s pursuit 
in a way which makes one laugh even at his own expense. He described it in 
its larva and chrysalis stages, and then as a perfect tormentor. The female flea 
was said to suck human blood and then disgorge it for her young, but as he had 
never seen it he could not vouch for its truth. Besides the common flea, whose 
scientific name was pulex irritans, and which was an external parasite, there 
was another in the West Indies (the jigger) which inserted itself into the flesh 
under the toe nails, and sometimes caused mortification of the foot. Many of 
the parasites laid their eggs under the skin of animals, and a large number were 
thus useful to men. He instanced how one would puncture the body of some 
unlucky caterpillar in a number of places and insert the eggs. The young 
developed and lived upon the body of the caterpillar, carefully avoiding the 
vital parts, but when on the point of turning into the chrysalis state the cater- 
pillar died, and the insects were set free in great numbers to repeat this process 
upon other caterpillars. He remarked that at the Southport aquarium he found 
a parasite feeding upon a sea anemone which bore such a striking likeness to 
one which attacks the whale that he was astonished. The same thing had been 
observed in America, but how it was that the same creature could exist upon a 
warm-blooded creature like the whale, and at the same time derive nourishment 
