THE ORGANS OF TACT1I.K SENSATION. 377 



swelling of the supplemental toe (in the male). In these parts the 

 division takes place at the deeper surface of the glands (Langer). 



A peculiar arrangement of the cutaneous blood-vessels is found in 

 the lamina inguinalis, where a chain of reddish points can be made 

 out with the naked eye; examined more carefully (Fig. 235 III) 

 each reddish point is found to be a complex loop of capillaries. 

 They extend from the skin to the hinder lymph-hearts, where they 

 form a close network which partially invests the lymph-hearts 

 (Langer). 



(2) The lymphatics of the skin (see also p. 252), like the 

 arteries, reach the deeper surface of the epidermis by coursing along 

 the bands of vertical fibres; they then form a network of capil- 

 laries with rounded meshes (Fig. 235 I, II, IV ), and lying imme- 

 diately under the epidermis, and a network which surrounds the 

 various glands. The lymphatic-capillaries are as a rule larger than 

 the blood-capillaries. The lymphatic network lies beneath the 

 blood network, and the vessels of the two systems branch indepen- 

 dently (Langer). 



In those parts where the glands are placed closely together this 

 arrangement is modified, and corresponds with the modifications 

 found in the blood-capillaries in these regions. The vertical branches 

 divide so as to form a network below the glands, and from this ver- 

 tical branches pass in the same direction between the glands to form a 

 secondary network on the superficial surface of the glands (Langer). 



g. The nerves of the skin. The cutis is very richly supplied 

 with both medullated and non-medullated nerves. In the subcuta- 

 neous tissue the nerves destined for the skin branch freely to form 

 numerous fine twigs, which, without actually inosculating, form a 

 fine mesh work. From the larger trunks numerous vertical branches 

 pass vertically to form a secondary network, from which both coarse 

 and very fine twigs pass to encircle the glands. The fine fibres which 

 supply the glands are non-medullated and possess oval nuclei j their 

 diameter varies from o - ooi-o - oo2 mm. The number of nerve-fibres 

 is not much smaller than that of the muscle-fibres (Engelmann). 

 (See also Organs of Tactile Sensation.)] 



II. THE ORGANS OF TACTILE SENSATION. 



The organs of tactile sensation are the nerve-plexus of the epi- 

 dermis, the touch-spots of Merkel, the lateral sense-organs, and the 

 touch-corpuscles of the tendons. 



