INFUSORIA. 



INFUSORIA. 



233 



Section 5. Enantiotreta. 



Mouth and anus terminal and opposite, reproduction effected by 

 transverse division. 



Enantiotreta nuda. 

 Family 7. Enchtlia. 



A. Mouth terminal, direct, obtuse, 



generally ciliated; division 

 of the body transverse. 



a. Body not ciliated, nor with 



hairs. 



* Simple. 



Genus Enchelyi. 

 * Double. 



Genus Ditoma. 

 aa. Body with vibratory cilice. 



Genus HoJophrya. 

 aaa. Body with cilia; not vibratory. 



* Subglobular. 



Genus Actinophryt. 

 '* Disciform. 



Genus Trichoditcut. 



B. Month terminal, oblique, often 



ciliated. 



b. Body without cilia. 



* No prolongation of the an- 



terior part. 



Genus Trithoda. 



** Anterior part prolonged into 

 the form of head and neck. 

 Genus Lachryinaria. 

 bb. Body ciliated. 



Genus Leucojihryi. 



Enantiotreta loricata. 

 Family 7. Colepina. 

 Envelope oval or cylindrical. 

 Genus Colepi. 



Levcophrti* patvla, with gome of the 

 gastric cavities full of food. 



Intestinal pystem of 

 Leucophryi patula. 



Section 6. Allotreta. 



Mouth and anus terminal and opposite, reproduction effected by 

 longitudinal and transverse divisions. 



A llotreta nuda. 

 Family 8.- Trachelina. 

 Mouth inferior, anus terminal. 



A. Mouth unarmed. 



a. No circle of cilise in front. 

 * Upper lip or front elongate, 

 cylindrical or depressed, pro- 

 longed into a narrow trum- 

 pet form. 



Genus Trachdiiu. 



** Upper lip short, depressed, 



and dilated obliquely. 



Genus Loxodet. 



* Upper lip compressed, sub- 

 carinate, or tumid. 

 Genus Buriaria. 

 aa. Front with a ring of cilia;. 

 Genus Phialina. 



B. Mouth armed with hooks. 



Genus Glaucoma. 

 Family 9. Ophryocercina. 

 Anus inferior, mouth terminal. 

 Genus Ofhryocerciu. 



Allotreta loricata. 



Family 8. Aspiditcina. 



Genus Aipiditcia. 



Section 7. Katotreta. 



Mouth and anus not terminal, reproduction as in the preceding 

 section. 



Katotreta, loricata. 

 Family 9. Euplota. 

 Body armed with hooks. 



A. Head indistinct. 



Genus Euplotes. 



B. Head separated from the body 



by a contraction. 

 Genus Discocephalua. 



Katotreta nuda. 



Family 10. Kolpoda. 



Body smooth or ciliated, unarmed. 



A. No eyes. 



A short retractile proboscis. 

 Body partially ciliated. 



Genus Kolpoda. 

 Body ciliated obliquely all 

 over. 



Genus Paraawecium. 

 aa. No proboscis. 



Front and tail contracted. 



Genus Ampkileptus. 



** Front oblong, tail contracted. 



Genus [froleptus. 



B. With eyes. 



Genus Ophryoglena. 

 Family 11. Ojnjtrichina. 

 Body ciliated and hairy, or armed 

 with styles or straight spiculte 

 and hooks. 



A. Body hairy, no styles or hooks. 



Genus Oxytricha. 



B. Body with hooks and no styles. 



Genus Kerona. 



C. Body with styles and no hooks. 



Genus Urostyla. 



B. Body with styles and hooks. 

 Genus Styltmichia. 



At the time this classification was drawn up, the distinctions that 

 limit the vegetable and animal kingdoms were less perfectly under- 

 stood than at present. One of the first members of this group of 

 organised beings that was withdrawn from the animal kingdom, was 

 the J)emidea:, which are now generally recognised as plants. [DissMl- 

 DE.E.] The group of Pseudopodia loricata must also be placed amongst 

 doubtful creations, although many physiologists do not hesitate to 

 group them amongst plants [Df ATOMACE.E], whilst the groups Monudina, 

 and Volvocina have recently undergone the most searching investi- 

 gation, with the result that many of these forms are more decidedly 

 vegetable than animal in their character. [VoLvox.] Some have 

 even gone further than this, and Agassiz in the ' American Journal of 

 Science,' for 1852, thus writes to Mr. Dana : " You may remember 

 a paper I read at the meeting at Cambridge, United States, in August 

 1849, in which I showed that the embryo which is hatched from the 

 egg of a Planaria is a genuine polygastric animalcule of the genus 

 Paramecium, as now characterised by Ehrenberg. In Steenstrup's 

 work on the ' Alternations of Generation ' [GENERATIONS, ALTEBNA- 

 TION or], you find that in the extraordinary succession of alternate 

 generations, ending with the production of Cercaria and its metamor- 

 phosis into Dtitama, a link was wanting the knowledge of the yourg 

 hatched from the egg of Diitoma. The deficiency I can now fill. It 

 is another Infusorium, a genuine Opalina. With such facts before us 

 there is no longer any doubt left respecting the character of all these 

 Polygastrica they are the earliest larval condition of worms. And 

 since I have ascertained that the Vorticellte are true Bryozoa, and 

 botanists claim the Anentera as Alga;, there is not a single type of 

 these microscopic beings left which hereafter can be considered as a 

 class by itself in the animal kingdom." Few naturalists would 

 perhaps indorse this statement of Professor Agassiz. The Vorticellcs 

 are not yet admitted as members of the family Bryozoa [POLYZOA] ; 

 nor are all the Anentera of Ehrenberg regarded indiscriminately as 

 A lijte. The passage however indicates the direction in which inquiry 

 is gradually breaking up the great polygastric family of Ehreuberg. 

 It is nevertheless very certain that many of the species enumerated 

 by Ehrenberg are only trausitionary forms in which the same being 

 . xists. To no one has this department of science been more indebted 

 than to Dr. F. Stein, who in his recent work, entitled ' Die Infusionsthiere 

 auf ihre Entwickelungs-Geschichte untersucht' (Leipsic 1854), has 

 given the result of a long series of investigations on this subject. 

 The following is a summary of Dr. Stein's researches, as recorded iu 

 this volume. (It ought however to be premised that Fdcke, 

 Dnjardin, and Siebold had previously pointed out that the great 

 mass of the Polygastric Infusoria were much simpler than Ehreuberg 

 had supposed, and that the internal organs he had described were 

 referrible to the general conditions of unicellular organisms, whether 

 animal or vegetable.) 



" In a glass iu which were contained a great variety of ciliated 

 Infusoria, and among them also numerous individuals of Euylena 

 riridit, Eacus, and Edties, Dr. Stein remarked, after the lapse of some 

 days, the formation of a thin film on the surface of the water, com- 

 posed of an interlacement of coufervoid filaments and Oscilluturice. 

 This film swarmed with Euylence, many of which had lost their bi'aks. 

 and crawled about with a worm-like movement among tlie Conferva 



