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POPULAE SCIENCE EEVIEW. 
well into two sub-classes, Dioecia and Monoecia ; the former including the 
Acanthocephala only, as being a peculiar tribe, and the latter being divided 
into tliree orders ; one characterized by the presence of neither mouth nor anus, 
the other by the presence of a mouth alone, and the third by the existence of 
both apertures 1 Indeed, except for convenience, we strongly object 
to the employment of the expression Entozoa, inasmuch as it seems to 
us nnadvisable to classify animals according to their habitats. It seems as if 
in the arrangement of the whole series of Annuloida, too little attention has 
been paid to morphological and physiological characters, and too much to 
distributional features. The proposal has been made to separate the Trema- 
toda from the rest of the so-called Entozoa, and by uniting to them the 
leeches and planarise to form a new order Suctoria, and we hope to see this 
method eventually adopted."^ 
It would be quite impossible to deal seriatim with the various chapters of 
Dr. Cobbold’s excellent book, in each of which we find ample space devoted 
to the history, anatomy, development, and habits of the species under descrip- 
tion. But we would refer our readers to the chapter on the Trichina, in 
which will be found full details concerning this singularly interesting parasite, 
and from which we quote the following conclusions which the writer gives as 
recorded by Leuckart, who has paid special attention to this species : — 
(1.) Trichina spiralis is the juvenile condition of a little round worm, hither- 
to unknown, to which, however, the generic name of Trichina must remain 
attached. (2.) The sexually mature Trichina inhabits the intestinal canal of 
numerous warm-blood animals. (3.) The second day after their introduction, 
the intestinal Trichinae attain their full sexual maturity. (4.) The eggs of the 
female Trichina are developed within the uterus of the mother into minute 
filaria-like embryos, which, from the sixth day, are born without their egg-sheU, 
(5.) The new-born young soon after commence their wanderings. They pene- 
trate the walls of the intestine, and pass directly through the abdominal 
cavity into the muscle of their bearers. (6.) The directions in which they 
proceed are in the course of the intermuscular connective tissues 
(15.) The immigration of Trichinee-brood in masses produces very grave, or 
even fatal consequences ; peritonitis (from the embryos perforating the 
intestinal walls), pain and paralysis (from the destruction of the infected 
muscular fibres).” 
The chapters on the subject of spurious helminthology should be read by all 
medical men, for they show that, in many instances, organisms may be found 
in the excrement of animals (man included), which, to the untrained eye, 
present the appearance of true entozoa, and yet may either belong to an 
entirely different group of beings, or may absolutely be portions of undigested 
food, or may, as in the following instance, be simply introduced into some of 
the excretions (that of the kidneys for example) to deceive the physician : — 
“ In the museum adjoining the Middlesex Hospital we have a Gordius, 
which was brought to an M.D. (since deceased), who, notwithstanding his 
eminence as a physician, was induced to believe that the worm in question 
* See on this subject a paper “ On the Affinities of the Groups Trematoda, 
Planariae, and Hirundinei. By Henry Lawson, M.D., in The Dublin Quarterly 
Journal of Science for 1861. 
