786 APPENDIX. 



tween the concentric laminre was equally hypothetical. In structure, 

 the Pacinian body, in fact, is identical with the corimsculum tactus — 

 being a solid mass of connective tissue, -whose apparent lamination de- 

 pends on the regular disposition of its elastic elements. We stated 

 further, that the central nerve-tubule gradually terminates, passing into 

 the central solid axis of the Pacinian body. In reality, the Pacinian 

 bodies are also nothing more than thickened processes of the neurilemma 

 of the nerve to which they are attached, and differ from the tactile cor- 

 puscles only in the circumstance that in the latter the thickening takes 

 place on one side of the nerve-fibril, while in the Pacinian body it takes 

 place on both sides. 



In the meanwhile, contemporaneous observations on this subject were 

 made by Leydig (" Ueber die Vater-Pacinischen Korperchen der 

 Taube") and by Kcilliker ("Einige Bemerkungen iiber die Pacinischen 

 Korperchen,") and were published in Siebold and Kolliker's " Zeit- 

 schrift," B. v., H. 1. 



Leydig and Kolliker's results are, in the main, in accordance with 

 our own, especially as respects the solidity of the Pacinian body. The 

 "central cavity" is given up by both, but Ktilliker still maintains the 

 existence of a fluid between the outer layers, at least in the Cat. Ley- 

 dig regards the central solid axis of the Pacinian body in the Bird as 

 the expanded termination of the nerve itself. 



Wagner had already drawn attention to the resemblance between the 

 corpuscula tactus and the Pacinian bodies ; Leydig further shows that 

 the latter form one series with the Savian bodies and the so-called muci- 

 parous canals of osseous and cartilaginous Fishes. We ventured, in the 

 paper in question, to add the "tactile hairs" or '■^ vibrissce" of Mam- 

 malia to this series of cutaneous organs, by showing that they are but a 

 further development of the muciparous canals — pointing out, at the same 

 time, that even the highest organs of sense, the Eye and the Ear, are 

 constructed upon the same principle. 



§ 2. Malpighian bodies of the spleen. — Having recently carefully 

 investigated the structure of these organs, we have arrived at the fol- 

 lowing conclusions [vid. " Quarterly Journal of Micr. Science," Jan. 

 1854). 



1. In the various animals examined (Man, Sheep, Pig, Rat, Kitten), 

 we find, as Dr. Sanders had already demonstrated in the Pig, that the 

 minute arterial twigs supplying the Malpighian bodies are not only dis- 

 tributed over, but enter and ramify in them, breaking up into their fine 

 penicillate branches as they pass out. 



Furthermore, connecting these arterioles, there is a network of fine 

 capillaries, whose walls are hardly distinguishable, but which are readily 

 detected by using syrup, which retains the coloring matter in their con- 

 tained blood-corpuscles. 



