INVERTEBKATA, CRYPTOGAMIA, MICROSCOPY, ETC. 805 



externally to the supporting lamella, a layer of nerve-fibres which 

 forms a plexiform envelopment for the whole body. In its histological 

 characters, this layer appears to be similar to the ectodermal nerve- 

 fibre-layer, found by the Hertwigs in the Actinias. 



In all the Schizonemertini, as well as in Polia and Valencinia, the 

 layer has the same histological structure as in Carinella, but it differs 

 in position, for it lies between the circular and the outer longitudinal 

 muscular layer. This leads to the view that it is possible that this 

 layer is a greatly developed ectodermal musculature. In the Hoplo- 

 nemertini this sijecial nervous layer seems to have disappeared. 



Intestinal Worms in the Horse.* — H. Krabbe has published an 

 interesting account of the occurrence of intestinal worms in the horse. 



As the horse is sj)read over the greater part of the inhabited 

 world, and under conditions of life very varied, it might be supposed 

 that, like man and the dog, it would not be equally affected with 

 these parasites, nor with the same species. To determine with some 

 degree of accuracy the Eutozoa which in Denmark are found in the 

 intestinal canal of the horse, M. Krabbe examined, during the last 

 four years, the bodies of 100 horses which were brought for anatomical 

 purposes to the Veterinary College of Coi^enhagen, between the 

 months of September and April in each session. 



In these horses he found Tcenia perfoUata, 28 times ; T, mamillana, 

 8 times; Ascaris megalocephala, 16 times; Strongylus armatus, 86 

 times ; S. tetracantJius, 78 times (in 67 horses out of 86) ; and Oxyuris 

 curvula, twice. Of T. perfoUata the number found was mostly less 

 that 25 ; sometimes it was over, and twice between 100 and 200 were 

 found, while once no less than 400 were met with. In general they 

 were lodged in the caecum. T. mamillana of Mehlis, a Sjjecies over- 

 looked by Dujardin and most French writers on the subject, was 

 described and figured by Gurlt in 1831 ; generally less than 25, but 

 sometimes up to 72, were met with, mostly in the anterior part of the 

 small intestine [T. plicata R. was never met with). The Ascaria 

 never occurred in larger numbers than 11. S. armatus was never met 

 with in the small intestine ; in the caecum it was common ; much less 

 so in the first portion of the colon, where very fine specimens of a 

 dark bluish red colour were found ; generally the number met with 

 was below 25, but once nearly 200 were found. Of 1409 samples, 

 1029 were females and 380 males. S. tetracanthus was found in the 

 caecum and throughout the colon, and Oxyuris curvula also in the colon. 



The literature of this subject would appear to be very scanty, 

 and the author ho2)es tliat the attention of veterinary surgeons in 

 other parts of tbe world may bo attracted to it. Ample oppor- 

 tunities of following it up exist in British India, America, and the 

 Cape of Good Hope district. 



Parasites of Helminthes.t — M. Moniez directs attention to a 

 somewhat curious fact. The EchinorhyncJii have generally been 



• 'Overs. K. Dansk. VicJinsk. Stlsk. Forlj.,' 1880, p. 33, aud 'FriicIi Rc'auniV 

 1». 9. Sc(! ' Niituro," xxii. (lf<8()) j). 217. 



t ' Hull. Sfi. Dt'p. Nur.l,' iii. (IHSll) p. liOL 



