PMlodinaea.l iNFrsoniAL animalcttles, 007 



moving the foot, and two belonging to the rotary organ. Sometimes, 

 says Dr. Ehrenberg, four anterior longitudinal muscles, and a 

 dorsal aod ventral muscle appear to be present. It has two kinds of 

 locomotion, one by alternately attaching the mouth and foot, and, as 

 it were, stepping along ; the other by swimming, from the action of 

 the rotatory apparatus. If the creature attaches itself by the foot, 

 and the rotatory apparatus is in motion, a strong current or vortex is 

 produced on each side the wheels, resembling two spirals in the 

 water, which bring the nutritive particles to the mouth, from which 

 some are chosen, and the rest flow away. For obsei'ving this action 

 with effect, finely divided carmine or indigo must be mixed in the 

 water. The nutritive apparatiis commences with a ciliated mouth, 

 opening anteriorly, just beneath the hook-like proboscis ; the cavity 

 of the mouth is a long extensible tiibe, having posteriorly an oeso- 

 phageal head, with four muscles, and two striated jaws with double 

 teeth {zygogomphia). The oesophagus communicates with a filiform 

 alimentary canal, which runs along the body, and has posteriorly an 

 oval expansion near its opening, at the basis of the tail-like foot. A 

 thick glandular cellulose mass, often yellowish or greenish, surrounds 

 the alimentary canal ; its use is unknown ; Dr. Ehrenberg thinks it 

 may be a coecal appendage, or sexual glands ; anteriorly are two 

 biliary glands. The propagative system is very interesting ; the 

 ovarium is a globose glandular mass ; in it four or five ova sometimes 

 so completely develope themselves, that the young creep out of their 

 envelopes, extend themselves, and put their wheels in motion while 

 in it. They sometimes occupy two-thirds the length of the parent. 

 In the ovum the young are coiled up in a spiral manner. A con- 

 tractile vesicle exists, along with a vascular system, indicated by eleven 

 or twelve parallel transverse vessels, and the respiratory tube at the 

 neck. The latter was formerly considered a sexual organ. The two 

 red frontal eyes, with ganglion beneath them, are evidences of a 

 nervous system. These eyes are cells, filled with a granular pig- 

 ment, and sometimes separate abnormally into several ; so that 

 Dr. Ehrenberg thinks no crystalline lens exists, but, it may be, they 

 are compound, like the eyes of insects, to determine which will re- 

 quire a microscope possessing enormous penetrating power ; a quality 

 discovered by Dr. Goring, and amply explained and illustrated in 



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