422 STRUCTURE OF THE SKIN 



for the reception of tactile impressions; an opinion purely hypo- 

 thetical and erroneous ; Chaussier, that the skin was composed 

 of but two parts, the dermis and epidermis, and that 

 which had been called the rete mucosum was probably a 

 part of the dermis ; Blandin,* that the rete mucosum, consist- 

 ing of three layers according to Dutrochet placed between the 

 papillary bodies and the epidermis, had neither vessels or 

 nerves, was a product of secretion from the papillae, like the 

 epidermis, and formed in fact a second epidermis thicker and 

 softer than the external, and that it had no more vitality than 

 the hair and nails. 



-Breschet and Roussel de Vauzeme,f have in this uncertain 

 and imperfect state of our knowledge, endeavored with the 

 aid of the scalpel and the microscope, to determine positively 

 its structure. Their researches have been extended not only 

 to the skin of man, but to that of whales and others of the 

 cetaceae. The discoveries which they allege to have made are 

 surprising, and though their researches appear to have been 

 made with much labor and ingenuity, their confirmation 

 or overthrow must depend upon the investigation of others 

 equally familiar with the same instruments. 

 But it must not be forgotten that such high magnifying 

 powers as they have used, expose the most wary and honest 

 observer to optical illusions. This cause led De la Torre, to 

 assert that the globules of the blood were annular. 

 According to these writers, the skin consists of but two layers. 

 The derm, or cutis vera, and an external layer, which they call 

 indifferently epidermis, corneous matter, corneous tissue, or 

 epidermic layers. This external layer comprises the rete muco- 

 sum and epidermis of other writers, and they consider it composed 

 of the same substance, mucus, in a greater or less state of desic- 

 cation. It is, however, composed of many distinct parts, not 

 arranged in the form of layers. Fig. 112, represents an imagi- 

 nary scheme or plan, in which they have placed together the 



* See Anat. Generale of Bichat, Paris, 1831. 



f Nouvelle recherches sur la structure de la peau, par G. H. Breschet and 

 Roussel de Vauzeme. Paris, 1835. 



