44, COBBOLD, ON ENTOZOA. 
their host, and in nearly all are at any rate productive of 
more or less discomfort and disease. 
The number, therefore, of these parasitic creatures through- 
out the entire animal kingdom is enormous, and their study, 
consequently, to be effectually carried out, must be pursued 
by those in a measure specially devoted to it. Amongst 
these, in this country at least, none ranks higher than Dr. 
Cobbold, who has for many years been so favorably known 
for the unwearied zeal and assiduity with which he has followed 
the study of helminthology by observation and experiment. 
The pages of this journal have so often been the vehicle 
for observations having reference to this subject, which is 
one, in fact, from the minuteness in many cases of the objects 
themselves, and in others from the peculiarity of their struc- 
ture, especially demanding microscopic research, that we do 
not hesitate to call the attention of our readers to the present 
work, which may be regarded as the first important original 
systematic treatise on helminthology in the English language ; 
as it is also one which, from the copiousness and value of its 
contents, the ease of its style, and, it may be added, the 
luxurious elegance with which it has been published, reflects 
the highest credit upon its author and his enterprising pub- 
lisher. 
We have termed it a work on helminthology, though more 
strictly speaking it is confined more particularly to human 
parasites. But as it is impossible to treat so fully of these as 
Dr. Cobbold has done, without entering at the same time very 
largely into the history of these creatures generally, his work 
may be regarded as conveying a tolerably complete view of 
the present state of helminthological knowledge in its whole 
extent. In fact, it may be said, that among the thirty or 
forty entozoa infesting man, are to be found nearly all of the 
types under which they exist throughout the animal kingdom. 
We are unable to enter into many particulars of the matter 
contained in the volume, but are desirous of saying a few 
words on the subject of the classification of entozoa adopted 
by the author. Dr. Cobbold is “satisfied that the method of 
retaining the entozoa as a distinct group is fraught with 
advantages more than counterbalancing the apparent ortho- 
doxy which a rather more exact and systematic treatment of 
the subject might involve.” And that the “ happiest and 
perhaps after all the most truly philosophic way of studying 
them is to regard them as a peculiar fauna destined to occupy 
an equally peculiar territory,” &c. 
The latter is an ingenious though fanciful conceit, and in a 
monograph of this kind there may perhaps be some present 
