Observations on Notommata Werneckii. By Prof. BaTbiani. 533 



In 1874, M. Maxime Cornu sent me some filaments of V. ter- 

 restris, on -which he observed numerous swelhngs containing 

 animalculre which he recognized as Rotatoria. I saw that they 

 were N. Werneckii, and eagerly proceeded to study this curious 

 rotifer. 



II. — Organization of N. Wernecldi. 



On examining the tubes of the Vaueheria, I distinguished on 

 the greater number two kinds of laterally placed excrescences : — 

 the oue easily recognizable as the organs of reproduction, from 

 their characteristic form (Plate XVIII., Fig. 1, o, o; Fig. 14) ; 

 the other much larger, generally club-shaped, representing a kind 

 of pocket, or elongated capsule, nearly at right angles to the 

 principal filament, and having the same green colour (Fig. \,c/,g). 



1 opened one of these, and saw the parasite gradually disengage 

 itself from the green matter. It was a blackish and extremely soft 

 body, continually contracting and modifying its shape. At its 

 centre was a large round spot with ill-defined edges, black and 

 opaque with transmitted light (Fig. 9, m s) ; this spot represents 

 the contents of the digestive tube, and is the hlack spot observed by 

 Vaucher in the capsules of the Ectosperms, It is surrounded by 

 a circle of colourless refractive globules, having all the characters 

 of oil drops (Fig. 9, g r). Outside this was a wide, greyish, granular 

 zone, forming the cortical layer of the animal. With a magni- 

 fying glass it appeared to be homogeneous, but under the Microscope 

 was seen to be composed of numerous elliptical bodies, which were 

 easily recognizable as nearly mature eggs (Fig. 9, o). 



At intervals there appeared at opposite points of the body two 

 short prolongations, one bearing, anteriorly, vibratile cilia ; the 

 other ending in a little tail with two triangular points (Fig. 9). 

 These characters classed the animalcule with the Rotatoria, and 

 finally, its red eye-spot and its situation in the tube of a Vau- 

 eheria proved it to be the Notommata Werneckii of Ehren- 

 berg. 



This summary description refers to the adult animalcule, ready 

 to lay, when its body is much distorted and the internal organs so 

 much modified as to be almost unrecognizable. To form an exact 

 idea of its organization, it is advisable to take an adult animalcule 

 whose ovary does not yet contain mature eggs. 



Notommata Werneckii is a small rotifer not exceeding • 30 

 mm. in length. The body is fusiform when elongated, the swollen 

 portion being nearer to the anterior than to the j)osteiior extremity, 

 which is thinner than the former. It is divided, more or less dis- 

 tinctly according to its age, into seven segments, formed by trans- 

 verse folds of the cuticle, and capable of being retracted one within 

 the other (Fig. 2). The cephalic is the longest, the three middle, 



