ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 



of any kind, wliicli has been considered by some to be the only 

 protective. 



Dr. C. T. Hudson writes us that " Nothing could be more instructive 

 than these curious clusters. In the great majority of cases, each 

 rotifer was seen imbedded in a patch of glutinous secretion, which 

 was divided from the similar patches of the surrounding rotifers by 

 sharp straight lines, so as to give the whole group the appearance of 

 a tesselated pavement. Here and there the Philodines were glued 

 together by long tongues of the same secretion ; especially where the 

 fibres of the paper projected above the general surface, and by spoiling 

 the level, prevented the formation of a sharp bounding line. In 

 one case a rotifer had bored its way into the fibres of the paper, 

 and, unable to withdraw or contract itself, had formed the centre of 

 a whole group of others attached to it by radiating bands of glue. 

 In fact these beautifully clean groups gave ocular demonstration of 

 the truth of Mr. Davis's theory that the Philodines resist drought by 

 encasing themselves in a glutinous case of their own secreting : and 

 the efficiency of the protective was at once shown by putting the 

 strips in water, when the buried rotifers soon struggled into life." 



Hudson's ' Rotifera.'* — The one thing wanting in a microscopist's 

 library has hitherto been a fairly complete book on Rotifers with 

 a sufficiency of illustrations. The first part of Dr. Hudson's book 

 just published was received at the January meeting with acclamation, 

 not only on account of the publication, so long expected, having been 

 actually commenced, but even more on account of the reality having 

 go much exceeded the expectation. All known British species will 

 be illustrated with original drawings from life, while of those which 

 are not British, descriptions and figures of the most important will 

 be given. Of the drawings (reproduced on coloured folio plates) it is 

 impossible to speak too highly, though they will probably not surprise 

 those who are already familiar with Dr. Hudson's remarkable facility 

 for representing from life the organisms of which he has made him- 

 self the leading authority. The instalment of the text, which includes 

 the introduction, history of literature, classification, and haunts and 

 habits, shows that it will not be behind the plates in practical utility 

 to microscopists ; while the fact that Messrs. Longman are the 

 publishers is a guarantee that the issue of the remaining five parts, 

 with 25 plates, will not show any falling off from Part I. No 

 microscopist who takes any interest in pond-life can afford to be 

 without this book, which will also fill a gap in zoological literature 

 which has long required filling. 



Mr. P. H. Gosse is assisting Dr. Hudson in the production of the 

 book. 



Echinodermata. 



Haemoglobin in Echinoderms.t — Dr. W. H. Howell has discovered 

 a Holothurian whose coelomic fluid contains red, oval, nucleated 

 corpuscles, in addition to the white amceboid ones. The red colour 



* Hudson, C. T. (assisted by P. H. Gosse), ' The Kotifera or Wlieel Animal- 

 cules.* Part I., 40 pp. and 5 pis., large 8vo, London (Longmans) 1886. 

 t Johns-Hopkins Univ. Circ, v. (1885) p. 5. 



