278 F. Leydig on the Caudal Spine of the Lion. 



XXXIl. — On the Caudal Spine of the Lion. 

 By Franz Leydig*. 



The author took the opportunity of the death of a fine Lion 

 in the Zoological Garden of Stuttgart to investigate the struc- 

 ture of the so-called "spine" in the end of its tail^ which 

 he found to be of more composite structure and of higher sig- 

 nification than has hitherto been supposed. In the specimen 

 examined it formed a perfectly smooth and naked wart, 2\ lines 

 in length and 1^ line in its broadest diameter. Its form was 

 like that of the papillre at the roots of human hair. Its colour 

 was lead-grey, partially tinged with red from blood shining 

 through it. The latter phenomenon, together with a certain 

 elastic softness, indicated at once that it could not be a simple 

 horny structure, which was confirmed by the microscopic ex- 

 amination of longitudinal sections. The latter showed clearly 

 that the so-called spine was in reality a papilla of the corium, 

 covered by a comparatively thin epidermis ; its horny layer was 

 colourless; and the cells of the rete Malpighii contained a few 

 pigment-granules. The ligamentous portion of the papilla, 

 which appeared very rich in blood even to the naked eye, showed 

 under the microscope, between the various columns and parti- 

 tions of the ligamentous substance and fine elastic fibres, arteries 

 0"0875 line in diameter with a thick muscular coat, and also 

 the corresponding veins. A nervous stem, O'l line in thickness, 

 was also very distinctly observed : this, in advancing, difi'uses 

 itself like a trellis-work, and sends out its fibrillse towards the 

 periphery of the papilla. Just as elsewhere in the Mammalia 

 the larger papillar elevations, both of the mucous membrane and 

 of the external integument, are beset with secondary papillse, so 

 also in this case. The entire free surface runs out into papillae 

 a little larger than those on the tips of the fingers ; the margin 

 is also, as it were, finely denticulated. Each of these micro- 

 scopic papillse contains a beautiful capillary ramification, but 

 no nervous threads can be traced into them. The skin of the 

 extremity of the tail, which bears the long hairs, is destitute of 

 papillse ; the hairs stand several together in one follicle ; the 

 sebaceous glands exhibited the ordinary form; the sudorific 

 glands formed elongated coils. 



From the foregoing statements, as the author remarks, it is 

 evident that the so-called caudal spine of the Lion is not, morpho- 

 logically, what it has hitherto been taken for. He sums up his 

 observations as follows : — " The organ in question is a papilla 

 of the corium, furnished with vessels and nerves, and therefore, 



* Miiller's Archiv, 1860, p. 820 ; abstract by W. S. Dallas, F.L.S. 



