628 



SUPPLEMENT 



cule, and depicted it ; a circumstance which 

 has not been mentioned by Baker, and other 

 microscopic writers, who have described it. 

 It may be found in great plenty in stagnant 

 waters in spring and summer, and in infusions 

 of hemp seed and trcmella. Baker describes 

 it as follows : This singular minute water 

 animal, seen before the microscope, appears 

 to be exactly globular, without either head, 

 tail, or fins. It moves in all directions, for- 

 ward or backward, up or down, rolling over 

 and over, like a bowl, spinning horizontally 

 like a top, or gliding along smoothly without 

 turning itself at all. Sometimes its motions 

 are very slow, and at other times very swift ; 

 and when it pleases, it can turn round as 

 upon an axis very nimbly, without moving 

 out of its place. The body is transparent 

 except where the circular spots are placed, 

 which are its young. The surface of the 

 body in some is, as it were, dotted all over 

 with little points, and in others, as if granu- 

 lated like shagreen. Baker thought also that 

 in general it appeared as if it were set round 

 with short movable hairs. By other writers, 

 they are thus described : These animalcules 

 are at first very small, but grow so large as to 

 be discerned with the naked eye ; they are 

 of a yellowish green colour, globular figure, 

 and in substance membranaceous and trans- 

 parent. In the midst of this substance several 

 small globes may be perceived ; each of these 

 is a smaller animalcule, which has also its 

 diaphanous membrane, and contains within 

 itself still smaller generations, which maybe 

 distinguished by the assistance of very powerful 

 glasses. The larger globules may be seen 

 to escape from the parent, and then increase 

 in size, as has been already observed. 



VOLVOX SPECIES. 



1 . Volvox pundum. Spherical, of a black colour, with 

 a lucid point. 2. Volvox granulum. Spherical and 

 green, the circumference of a bright colour. 3. Volvox 

 globuhts. Globular volvox, the hind part somewhat 

 obscure. 4. Volvox pilula. Small round volvox, with 

 immovable green intestines. 5. Volvox yrandinella. 

 Spherical and opaque, with immovable intestines. 6. 

 Volvox socialis. Spherical volvox, with crystalline 

 molecules, placed at equal distances from each other. 

 7. Volvox sphcericula. Spherical volvox, with round 

 molecules. H. Volvox lunula. An hemispherical volvox, 

 with lunular molecules. 9. Volvox ylobator. Described. 

 10. Volvox morum. Membranaceous, orbicular, with 

 Spherical green molecules in the centre. 11. Volvox 

 uva. Globular volvox, composed of green spherical 

 globules, which are not inclosed in a common mem- 

 brane. 12. Volvox vcgetans. Vegetable volvox. Des- 

 cribed. 



IV. ENCHELIS. An invisible, simple, cy- 

 lindric worm. 



" This genus of animalcules, according to 

 Miiller, contains twenty-seven species. The 

 size of the dilFerent species varies considerably, 

 and therefore requires different magnifying 

 powers to develope them (from 200 to 500 li- 



near.) If the reader have an opportunity of 

 examining any of them, in instruments of dif. 

 ferent constructions, but of the same magnify- 

 ing power, he will readily perceive there is 

 something beyond mere amplification that is 

 essentially requisite in a microscope, in order 

 to show the details of objects." 



Plate 35, fig. 61. The Egg -shaped Enchelis. 

 " This animalcule is distinguished by its pellu- 

 cid appearance and the longitudinal folds of 

 the external membrane. A few bright spots 

 are also sometimes observed ; these have been 

 supposed to be the ova, but it is more probable 

 they are the sacs of the polygastric structure. 

 The figure is a magnified representation, show- 

 ing the sacs and folds, neither of which are 

 constant. Found in stagnant water." 



Plate 27, fig. 30. EneJielis punctifera. 

 Green enchelis, subcylindric, the fore-part ob- 

 tuse, the hinder part pointed. This is an 

 opaque animalcule, of a green colour. The 

 hinder part is pellucid and pointed ; an inci- 

 sion is discovered at the apex of the fore-part, 

 which seems to be the mouth. It is found in 

 marshes. 



Plate 27, fig. 45. Enchelis rttrograda. 

 Transparent enchelis, the fore-part rather 

 smaller, and terminating in a small globule. 

 It has a gelatinous, diaphanous body; no vi- 

 sible intestines, though a pellucid globule is 

 discoverable near the hinder part ; the body is 

 thickest in the middle, and grows smaller to- 

 wards each end. It generally moves side- 

 ways, sometimes in a retrograde manner ; and 

 if it be obstructed in its motion, draws itself 

 up, as represented in the figure. 

 ENCHELIS SPECIES. 



1. Enchelis viridis. Green enchelis, of a subcylindric 

 figure, the fore part truncated. 2. Enchelis punctifera. 

 Described. 3. EncMis deses. Green, cylindrical, gela- 

 tinous, the end somewhat pointed. 4. Enchelis simi/is. 

 Egg-shaped, with opaque movable intestines. 5. EitcJtells 

 serotina. Partly oval, partly cylindrical, the interior parts 

 immovable. 6. Enchelis nebulosa. Oval and cylindri- 

 cal, with visible movable intestines. 7. EncMis semi- 

 nulum. Equally cylindric. 8. Enchelis intermedia. Cy- 

 lindrical, transparent, with a blackish margin, 9. En- 

 chelis ovulum. Egg-shaped. Described. 10. Enchelis 

 pirum. Pear-shaped, the hinder part transparent. 1 1 . 

 EncMis tremula. Oval, cylindrical, gelatinous. 12. En- 

 chelis constricia. Sub-oval, crystalline, with a stricture 

 in the middle. 1 3. Enchelis pulvisculits. Elliptic, with a 

 congeries of green intestines. 1 4. Enchelis fusus. Cylin- 

 drical, both ends truncated. 15. Enchelis fritillus. Cy- 

 lindric, the fore-part truncated. 16. Enchelis caudata. 



f/cmmata. Body cylindrical, upper part prolonged into a 

 transparent neck , a double series of globules running down 

 the body. 19. EncMis retrnyrada. Described. L'O. En- 

 chelis festinans. Oblong, cylindrical, the ends obtuse, 

 the fore-part transparent. 21. Enchelis far cimen. Cy- 

 lindric, crooked and truncated at both ends. 22. En- 

 chelis index. Like an inverted cone, one edge of the apex 

 produced and forming an angle with the other part. 

 23. Enchelis truncus. Cylindrical, with a kind of head. 

 24. Enchelis Larva. Long, with two small nipples 

 projecting from the middle of the body, one on each 

 side. 25. EncMis spatula. Striated, the fore-part trans- 

 parent and of the shape of a spatula. 26. Enchelis pu- 



