ON MICROSCOPIC DISCOVERY. 



631 



VII. PAKAMJKICM. An invisible, simple, 

 membranaceous, flat, and pellucid worm. 



The animalcules includedinthisgenus, toge- 

 ther with the kolpoda, are supposed by Ehren- 

 berg to be the same as the monads and cycli- 

 dia, at a more advanced stage of their growth. 



Plate 35, fig. 63. Paramacium chrysalis. 

 " These ..interesting creatures appear like 

 milk-white specks to the naked eye. They 

 are soft, and yield to the presence of any hard 

 substance they may come in contact with. 

 The body is long, and in some positions the 

 cuticle appears to have a diagonal fold, as 

 shown in the figure. The mouth aperture is 

 situated on the inferior side, near the middle, 

 and in some views it appears like a papillary 

 projection. In good microscopes, the body is 

 seen covered with longitudinal rows of hair ; 

 hy means of these, the creature is enabled to 

 produce a current in the water towards its 

 mouth. They propagate by transverse divi- 

 sion. These animalcules are well adapted for 

 showing the structure of the alimentary or- 

 gans, as they are of sufficient magnitude to 

 render the sacs clearly distinguishable, when 

 filled with coloured particles. On the intro- 

 duction of indigo into the water they are 

 greatly agitated ; in a few minutes, however, 

 they are quiet ; and the digestive sacs become 

 coloured, as in the figure, when from 100 to 

 200 may be enumerated. Length, l-85th to 

 t -200th of an inch." 



1. ParamcEcium aurelia. Compressed, oblong:, folded 

 towards the fore-part, hinder part acute. '2. Paramae- 

 ciiuit chrysalis. Cylindrical, folded towards the fore- 

 part, hinder part obtuse. Described. 3. Puramcecium 

 wrsutum. Cylindrical, lower part thick, both ends very 

 obtuse. 4. Parameeclum oinfei-um. Depressed, with 

 large oval molecules withinside. 5. Paraiiuecium maryi- 

 na/um. Depressed, gray, with a double margin. 



VIII. KOLPODA. An invisible, very sim- 

 ple, pellucid, fiat and crooked worm. " They 

 vary much in external form." 



Plate 35. fig. 64. The cuckoo Kolpoda, or 

 Common Bosom animalcule, " Its general 

 contour has some resemblance to a bean ; and 

 if we suppose the two convex lobes on the 

 front side equal, and do not perceive the pro- 

 boscis, which indeed is seen with difficulty, we 

 shall distinguish some likeness to the bosom ; 

 from which similitude it lias received its name. 

 The mouth, which is more lightly tinted than 

 the surrounding parts, is situated in the hollow 

 between the upper lobe and the proboscis, and 

 marked by a cross, while the termination of 

 the alimentary canal is in the cavity immedi- 

 ately below the proboscis. The margin of the 

 two lobes isfurnished with arowofdelicatecilia, 

 only observable under favourable illumination. 

 These cilia, by producing a current in the 

 water towards the mouth, perform the same 



important offices as members in some of the 

 mammalia; as the current brings all the par- 

 ticles of matter in the water to the mouth in 

 regular succession. By feeding these animal- 

 cules on vegetable colouring, the poly gastric 

 form of their digestive organs is readily dis- 

 tinguished. Length of full grown specimens, 

 1.280th of an inch. They are found in vari- 

 ous vegetable infusions, and especially in 

 those of hay which have been kept a consider- 

 able time." 



KOLPODA SPECIES. 



1. Kolpoda lamella. Elongated, membranaceous, 

 hinder part curved. 2. Kolpoda gallinula. Oblong, 

 back towards the fore-part bright and membranaceous. 

 3. Kolpoda rostrum. Oblong, the fore part hooked. 

 4. Kolpoda ochrea. Long, membranaceous, apex at- 

 tenuated, base bent in a right angle to the body. 5. 

 Kolpoda mucronata. Membranaceous, dilated, fore-part 

 smaller than hind-part, with a small incision at one- 

 side. 6. Kolpoda triquetra. Egg-shaped, one edge 

 turned back. 7. Kolpoda striata. Oblong, pear-shaped, 

 white, fore-part pointed, hind-part round. 8. Kolpoda 

 nucleus. Egg-shaped, with an acute vertex. 9. Kolpo- 

 da mdeagris. Changeable, the fore-part like a hook, 

 the hind -part folded up. 10. Kolpoda assimilis. De- 

 pressed, apex in the form of a small hook. 1 1. Kolpoda 

 cucullus. Described. 12. Kolpoda cucullidus. Oblong, 

 with an oblique incision a little below the apex. 13. 

 Kolpoda cucullio. Flat, oval, bending slightly beneath 

 the apex. 1 4 . Kolpoda reu. Thick and curved in the 

 middle. 15. Kolpoda pimm. Convex, oval, apex formed 

 into a kind of beak. lt>. Kolpoda cuneus. Clavated, 

 round, the apex dentated. 



IX. GONIUM. An invisible, simple, smooth, 

 angular worm. 



" The animalcules of this genus are in 

 clusters ; they are propagated by several inci- 

 sions across the body of the parent, dividing it 

 into a number of symmetrical forms. When 

 observed singly, most of the species resemble 

 the volvox. The structure of their digestive 

 organs is not known." 



Plate 35, fig. 69. 'The Brtast-phite Go- 

 nium. " It consists of sixteen spherical bodies, 

 disposed regularly in a quadrangular form, like 

 the jewels in the breast-plate of the Jewish 

 high-priest. They are all arranged in the 

 same plane ; the four centre ones are general- 

 ly longer than those which surround them ; 

 and the diameters of the three smaller balls 

 are only equal to the two larger centre ones to 

 which they are attached ; the external corners 

 are therefore vacant. The diameters of the 

 clusters vary from 1 -3500th to 1 -200th of an 

 inch. They are found near the surface of 

 clear water, and often along with the cercaria 

 viridis. A magnifying power of 200 is suf- 

 ficient for their examination." 



GONIUM SPECIES. 



1. Goniwn pedorale. Quadrangular, pellucid, with six- 

 teen spherical molecules. Described. 2. (Ionium pvl- 

 viaatum. Quadrangurlar, opaque, with four little pil- 

 lows. 3. Gonium Corrugatum. Quadrangular, white, 

 sunk a little in the middle. 4. Gonium rectanyulum, 

 Rectangular, hind part arched. 5. Gonium truncation. 

 (ionium with obtuse corners, hind-part arched. 



