829 



MICROSPORON. 



MIDAS. 



830 



In preparing this article we have been greatly indebted to Dr. Beale's 

 most useful work on the ' Microscope, and its Application to Clinical 

 Medicine,' also to the translation of Dr. Schacht's work on the 

 ' Microscope in its special Application to Vegetable Anatomy and 

 Physiology,' translated by Mr. Currey, and to Professor Quekett's 

 admirable * Treatise on the Microscope.' For those who would wish 

 to refer to the subject further we give a list of the principal works 

 devoted to this instrument: Robert Hooke, ' Micrographia, 1667. 

 Leeuwenhoek, ' Papers in Philosophical Transactions," from 1673. 

 Baker, ' Employment for the Microscope,' 1744. Adams, 'Micrographia 

 Illustrated ; or, the Knowledge of the Microscope Explained," 1746. 

 Adams, jun. 'Microscopical Essays, 1787. Pritchard, ' Microscopic 

 Cabinet.' Chevalier, ' Des Microscopes et de leur Usa;e.' Sir David 

 Brewster, 'Treatise on the Microscope." Joseph Jackson Lister, 

 'Philosophical Transactions," 1829. Ross, article 'Microscope,' in 

 ' Penny Cyclopaedia," 1839, Carpenter, article ' Microscope," in ' Cyclo- 

 paedia of Anatomy and Physiology." Mandl, ' Traite Pratique du 

 Microscope,' 1839. Schleiden, ' Principles of Scientific Botany,' trans- 

 lated by Dr. Lankester, appendix ' On the Use of the Microscope," 

 1849. Robin, 'Du Microscope et des Injections.' Hannover, 'On the 

 Microscope," translated by Professor Goodsir, 1853. Bennett, 'An 

 Introduction to Clinical Medicine.' 1853. Hogg, 'The Microscope, 

 its History, Construction, and 'Application,' 1854. ' The Microscopical 

 Journal.' ' Quarterly Journal of Microscopical Sciences." Griffith and 

 Henfrey, 'The Microgrnphical Dictionary,' 1854-55. 



MICRoSPORON. [ENTOPHYTA.] 



MICROTUS, Schrank's name for a genus of Murine Rodents, 

 embracing our English Water-Rat, Mui ampkibius, Linnaeus, &c. 



[MUBID-E.] 



MICROZOA'RI^ (literally 'little animals'). This is the title 

 employed by M. De Elainville for the Animalcula infusoria of earlier 

 writers, who commonly classed these singular objects of microscopic 

 research among the Zoophyta. Baker, Needham, Buffou, and Spal- 

 lanzani, occupied with the singular facts and hypotheses regarding the 

 origin and vitality of these animated points, gave little attention to 

 their zoological relations ; the works of Limueus contain almost no 

 notice of more than the larger Vorticella, Brac/iioni, and Volvoces, 

 which are ranked among the Vermet Zoophyla. The great founder 

 of all the classifications of the minute Infusoria, the first; careful 

 observer of their permanent characters of form, surface, movements, 

 and internal structure, is the accurate 0. F. Mttller, author of the 

 ' Zoologia Danica.' Considering that in 1786 (the date of his work) 

 the microscope had been scarcely at all improved since the days of 

 Hooke, the numerous figures which Miiller presented were highly 

 creditable to his eye and hand. They have been frequently copied 

 (as in the ' Encyclopedic Me'thodique '), and yet retain a high value. 



Muller'a classification, founded upon the figure and surface of the 

 animal, is convenient to the observer who desires to name the active 

 molecules which pass under his microscope, but unsatisfactory to the 

 zoological student. 



The genera are arranged in some degree according to their apparent 

 simplicity. 



A. Without external organs. 



* Substance thick. 

 Monat. A mere point. 



Proteia. Of variable figure. 

 Volrox. Spherical. 

 Enchdit. Cylindrical. 



Vibrio. Round, elongated. (Several of the animals included in 

 this group should have been ranked among the Vermes.) 



* Membranaceous. 



Cyclidium. Oval, complanate. (Generate by division.) 

 Paramecium. Of an oblong figure. (Generate by division.) 

 Jfolpoda. Sinuate, complanate. (Generate by division.) 

 ftonium. An angular mass. 



Burtaria.. Hollow like a purse. 



B. With external organs. 

 * Naked. 



Cercaria. With an extension like a tail Some are said to have 

 eyes. 



Trichoda. Named for its hairiness. (Generate by division.) 



Kerona. With little horny protuberances. 



Himantopui. With slender extensions or cirri. 



Leucopkra. Ciliated over all the surface. (Generate by division.) 



Vorticdla. Ciliated about the mouth, contractile. The ciliao have 

 a whirling motion. 



** Covered with a shell. 



Brachionui. Ciliated nearly as Vorticella. 



On thU classification Lamarck ('Animaux sans Vertebras') has 

 made few alterations ; he preserves the same genera nearly in the same 

 order in all the naked Infutoria, but rejects from those with external 

 organ* (Infusoires appendicules) Vorticella and Brachionui (which he 

 place* among his Polypi), and re-arranges the others thus : 



Infusoires appendicule's. 



No tail [ Frieda (including Leacophra of Miiller). 

 1 Kcrona (including ffimantopus of Miiller). 



A tail [ t ? erca '~ ia - 



\ Fitrcocercaria. 



The remaining groups are thus classed among the Polypi : 



Polypi ciliati. 



Section 1. Tibratiles with oral cilia;, having vibratory movement. 

 Rattulus. (Trichoda Rattus and T. clavus of Miiller.) 

 Trichocerca. (Cercaria forcipata, &c., Miiller.) 

 Vagirticola. (Trichoda inquilina, &c., Miiller.) 



Section 2. Rotifers, with orral cilise having rotatory movement. 

 Polliculina. ( Vorticella ampulla, V. raginata, &c., Miiller.) 

 Brachionui. (Divided into sections, with or without a tail.) 

 Furcularia. (Includes the Vorticella rotatoria, or wheel-animal and 



others allied to it.) 



Urceolaria. (Vorticella viridis, Bursaria, &e., Miiller.) 



Vorticella. (The pedunculated species of Miiller, both simple and 



compound.) 

 Tubicolaria. 



Cuvier constitutes for the Infusoria his fifth and last class of 

 Zoophyta, observing however, what always struck the least informed 

 zoologist, who contemplated the various forms and habits of these 

 animals, that among them were several grades of organisation, and 

 some forms which could not be reconciled to zoophytic structure. 

 Bory de St. Vincent had adopted ('Encyclope'die Me'thodique,' 1826) 

 82 genera, but Cuvier even reduces the number of Lamarckian gentra. 



De Blainville (' Actinologie ') gives the following arrangement of 

 the Microzoaria : 



Division I. Microzoaria heteropoda. 



Section 1. Rotiferw.- Body distinguished in parts anterior, mediul, 

 posterior (sometimes really showing head, thorax, and abdomen), with 

 anterior bundles of cilise, which in their rapid movement resemble 

 wheels. Posterior appendices simple, terminal. 



The genera are as in Lamarck, with indications of the sub-genera 

 adopted by Bory de St. Vincent. 



Section 2. Ciliiferce, with lateral ciliform appendices. The genera 

 are taken from Miiller, namely, Kerona, Himantopus, Paramacium, 

 Trichoda, Leucophra, Volvox, Cyclidium, Monas, with indications of 

 the sub-divisions adopted by Bory de St. Vincent, &c. 



Division II. Microzoaria apoda. 



With no external appendices, including Bursaria, Jfolpoda, Traclie- 

 Una (Vibrio, Miiller), Proteus, Cercaria, Enchelis, and Gonium. 

 Many of them are thought by De Blainville to be young Planarite or 

 Hii-udines. 



Nearly all the real information which accompanied these slight 

 transformations of Miiller's system of classification was derived from 

 the numerous and acute observations of that eminent naturalist, 

 whose figures and descriptions we have often compared with the 

 indications of the microscope before this instrument received the 

 marvellous improvements of Amici, Chevalier, Pritchard, Plosl, and 

 Schiek. By their inventions, and the able use made of them since 

 1828, a new mine of knowledge has been opened on the history, 

 structure, and zoological relations of the Infusoria. [INFUSORIA; 

 DIATOMACE.E ; DESMIDIE,E ; ROTIFEHA.] 



MIDAS, M. Geoffroy's name for a sub-genus of the small South 

 American Monkeys called Ouistitis. [JACCHUS.] The common name 

 for the species of this sub-genus is Tamarin. 



It has the following characters : Muzzle short, facial angle 60 ; 

 foreheaa with an appearance of prominence, arising from the great 

 angle of the upper edge of the orbits; upper incisors contiguous, 

 under incisors same size as the upper. Nails like claws, excepting 

 those on the thumbs behind. Tail as in Jacchus. General dental 

 formula as in Jacchui. 



There are seven species, of which we select as the example 

 M. Rosalia, the Marakiua, or Silky Tamarin. This pretty little 

 monkey is entirely of a golden-yellow, varying to a redder tint, and 

 palest on the back and thighs. The hair, which is fine and silky, is 

 so long about the head and neck as to form a ruff or mane, whence it 

 has been called the Lion-Monkey. Its beauty and gentleness render it 

 a very interesting pet; but great care is required to keep it from 

 damp, which is destructive to it. It is supposed to live almost 

 entirely on trees, and to be squirrel-like in its habits. 



It is a native of Guayana, and the south of Brazil from Rio Janeiro 

 to Cape Frio. 



Desmarest notices a red and black variety (Guyana), and one of a 

 bright shining red from Brazil. 



The species must not be confounded with M. Leonina, Simia 

 Leonina (Humb.), the Leoncito, or Leonine Tamarin, which is pro- 

 bably the smallest monkey known. The last is brownish, and has a 

 very well developed mane of that colour, which it bristles up when 

 angry, so as to look like a little lion. The face is black, the mouth 



