12 FISCHER ON THE PELYIS OF THE MAMMALIA. 



and hence, according to Tyson, it arises that the coccyx in the troglodytes 

 forms a protuberance under the skin (in this respect) the human embryo 

 strongly resembles the simiae.* The Lemur tardigradus has five coccygeal 

 vertebrae ; the papio mormon eight ; the papio maimon twenty ; the circo- 

 pithecus jacho twenty- seven ; the lemur mongoz and cercopithecus saniscus 

 thirty-three. The number of coccygeal vertebrae is never so constant as in 

 man ; whence it happens that the numbers observed by different persons vary, 

 often very much even in the same species. " The reason of this variation is to 

 be sought for in the observers themselves, not in the animals ; and to be con- 

 tained in the difficulty of deciding amongst the separate vertebrae of the pelvis, 

 what vertebrae are to be assigned to the sacrum, and what to the coccyx. 

 Three vertebrae only in the cercopithecus I have described can be assigned to 

 the sacrum. The wing-shaped portion of the first vertebrae on each side is the 

 only one which has a distinct union with the os ilium, quite otherwise there- 

 fore than in man, in whom the symphysis with the ilium extends as far as 

 and includes the first, second, and third, spurious, that is sacral vertebrae. 

 The two vertebrae which in the circo-pithecus now follow, and which form 

 with the first coccygeal vertebrae a kind of obtuse promontary in the middle 

 of the pelvis, have broad thin transverse processes, truncated at their extre- 

 mities, which unite with each other and with the first vertebrae by the angles 

 of their apices, or summits, and by means of a cartilaginous substance and a 

 ligamentous expansion ; the same is effected by an osseous substance in the 

 schunk, musteta, &c. Next come four coccygeal vertebrae perforated, short, 

 with narrow transverse processes and oblique processes still rather large, the 

 first of which has still a vestage of the dorsal spinous process, but the second 

 first shews the abdominal spinous process to be described below. The sixth 

 coccygeal vertebrae still shows on its upper surface the remains of the excava- 

 vation (foramen pro medulla spinali) which almost immediately ceases." 

 Autenreith. 



The first six vertebrae of the occyx in the cercopithecus-jacho, pa- 

 niscus, papio maimon, lemur mongoz, and briefly, in all the long-tailed 

 quadrumana, have true spinous processes which tend somewhat obliquely up- 

 wards ; from the same there proceed obliquely upwards on either side ascending 

 oblique processes, the rounded extremity of which is united to the posterior 

 surface of the descending oblique processes of the vertebrae above. Their 

 transverse processes are sufficiently long, inclining downwards and backwards. 

 These six superior vertebrae of the coccyx are perforated, which holds also in 

 the tail-less apes, in whom for the most part the os coccygis is composed of 

 three vertebrae, the simia troglodytes and satyrus excepted. In the last per- 

 forated vertebrae of the coccyx exists the end of the canal for the spinal 

 marrow, which Galen asserted also of man ; f but already this error had 

 been exposed by Vasalius, J who shewed that in man the canal for the spinal 

 marrow extended no farther than the os sacrum. The remaining coccygeal 

 vertebrae are longer, but towards the terminations they again become shorter 

 and more slender. The longest vertebrae of this region in the papio maimon 



* P. Camper; 1. c. p. 186. 



t Galen. Lib. de Ossibus. C. xi. 



% Vasalii de corp. human, fabrica. Basil, 1555. Ejus epistola rationem modamque, &c., 

 &c. Basil, 1546, p.p. 49. 



