346 



SCIENCE-GOSSIP. 



W. Saville Kent, in his " Manual of the Infusoria," 

 published shortly afterwards, supports Stein's 

 view. 



The body of A . viridis is elongate-ovate in shape, 

 and is from eight to ten times as long as broad 

 when fully expanded, and from 125 to 225 microns in 

 length. The anterior end istransparentand obliquely 

 truncate, and it is here that the red stigma is 

 situated. Dujardin says that it is bilabiate, and 

 that the flagellum springs from the upper lip, but 

 probably it is pierced by a tubular pharynx, as in 



Fig. 4. — Amblyopias virdis ( x 300). 



Euglena viridis, from the base of which this 

 appendage has its origin. The posterior end 

 is rounded. The endoplasm, except for the 

 anterior portion, is coloured bright green, and 

 bears numerous oval and rod-shaped amylaceous 

 corpuscles. The green matter Ehrenberg con- 

 sidered to be composed of the animal's ova, the 

 rod-like amylaceous corpuscles genital organs, 

 and he called a globular mass situated under 

 the stigma, which is probably in reality the reser- 

 voir of the contractile vacuole, the nervous 

 ganglion. The contractile vacuole as in Euglena 

 viridis. This animal is common in ponds and 

 ditches, and moves in a slow and vacillating 

 manner. 



Trachclomonas volvocina Ehr. — This is a small 

 green Euglena-like organism, enclosed in a smooth 

 sub-spherical or ovate indurated sheath or lorica, 

 which is red in colour and appears under the 

 microscope as a crimson band surrounding the 

 animal itself, and forming a pleasing contrast to 

 its green-coloured endoplasm. This hard case is 

 perforated at one point to allow the flagellum to 

 pass through it, and round this hole a collar-like 

 projection of varying size may be raised. The 



Fig. 5. — Trachclomonas volvocina (x 500). 



structural details of the organism are more or 

 less the same as in Eugicna ; this aperture also 

 serves as a means of entrance for food particles. 

 While under ordinary circumstances all except the 

 flagellum is enclosed within the lorica, yet it has 

 been observed by Perty and Stein that under 

 certain conditions the body squeezes out through 

 the minute anterior aperture, and swims about 



naked, or rather without its armour, like an 

 ordinary little Eugicna. "This feat," says Saville 

 Kent, " appeared to Stein to be as difficult of 

 achievement as the passage of the biblical camel 

 through the needle's eye," yet we are led to infer 

 that even this is possible. The diameter of the 

 lorica is from 25 to 35 microns, and the flagellum, 

 which is slender and somewhat difficult to see, 

 may be as much as double or treble this in length. 

 It is, however, readily seen on killing the animal 

 with osmic acid. 



This animal may be found in fresh water among 

 confervae. It is sluggish in its habits, and often 

 appears to lose its flagellum and settle down to 

 rest ; in fact I have observed quite as many in 

 this condition as engaged in more or less active 

 peregrinations. It is one of the most common 

 of freshwater Infusoria, and yet for some reason 

 or other it usually escapes notice in the various 

 popular works on "Pond Life." Its small size 

 and unobtrusive habits may perhaps account for 

 this neglect. 



Trachclomonas hispida Perty. — This differs from 

 T. volvocina in having the lorica ovate or elliptical, 

 and covered evenly with minute points, or hisps, 

 instead of being perfectly smooth ; the red colour 

 is also not quite so pronounced. I observed a 



Fig. 6. — Trachclomonas hispida ( x 500). 



variety in which the hisps were more pronounced 

 round the anterior aperture than in other parts. 

 The length is from 22 to 48 microns and is from 

 one and a-half to two and a-half times as great as 

 the breadth. As in the former species, there is a 

 collar round the anterior aperture which varies in 

 depth. 



T. hispida is as common as T. volvocina, resembles 

 it in size, and is found in similar situations. It was 

 described first by Ehrenberg, in 1832, under the 

 name Chaetoglena volvocina, from specimens taken 

 by him among confervae in the neighbourhood of 

 Berlin ; and, according to Stein, it is also identical 

 with Choncmonas hispida and C. schranhii of Max. 

 Perty 



Trachclomonas euchlora Ehr. — The lorica is colour- 

 less and smooth, is oval or elliptical in shape, and 

 is about one and a-half times as long as broad, the 

 length being from 20 to 40 microns. The anterior 

 aperture is produced into a short tubular obliquely 

 projecting neck. This species was described by 

 Stein under the name T. lagenella, and although he 

 recognized that it was identical with Lagenella 



