1868. | Zoology. 593 
the first place there are fishes which belong to the genus Fverasfer, 
these pass in through the water-tree, or lung, of the animal, they 
are true parasites, feeding within the Holothuria; then there are 
several small Crustacea; and thirdly, the Molluse Entoconcha, de- 
scribed by Johann Miller, from Synapta. Dr. Carl Semper describes 
these in his work on the Echinoderms of the Philippine Islands, 
and also mentions a new Entoconcha which lives in a true sea- 
cucumber ; he also describes parasitic species of Hulima ; and most 
interesting of all, a little Lamellibranch which lives on the skin of 
Synapta, and crawls with a large membranous foot, whilst its shell 
is so much invested by the mantle as to be completely internal. 
An addition to the parasites of the Holothuroid Echinoderms was 
made last year by Mr. Ray Lankester, who discovered a very re- 
markable Rotifer in great abundance amongst the genitalia of the 
Synapta Sarniensis and inhewrens, at Guernsey. 
PuystoLoGy. 
New Bodies discovered by the Spectroscope.—We would direct 
special attention to the very remarkable report of Dr. Thudichum, 
issued by the Medical Officer of the Privy Council in his last (tenth) 
Blue Book. Dr. Thudichum sketches in a masterly manner the 
history of past chemical researches into the functions and products 
of the human organism. He then describes some of his own 
researches, apparently carried out within the year, and which have 
yielded most extraordinary results. New bodies determined by 
their optical properties are described im this report at the rate of 
about three a page. This is rather rapid work, and does not leave 
a very satisfactory impression on the mind. Some most interesting 
fluorescent products from the chemical decomposition of blood, of 
albumen, and of urine are described, of which we are most anxious to 
hear or see more. ‘The spectroscope used by Dr. Thudichum appears 
to have been an excellent one; but his method of examining only one 
thickness of a coloured body, has, we fear, led to some misappre- 
hensions as to new bodies. Some of the spectra drawn as new are 
highly interesting and no doubt indicate new bodies, as, e.g., cru- 
entine and its products; but others are old and well known to all 
physiologists, though Dr. Thudichum “reports” them as though 
previously undiscovered. This is a bad sign, and coupled with the 
hasty appearance of the work does much to diminish the value of 
what seems otherwise likely to prove a very notable and grand 
addition to the knowledge of animal chemistry. 
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