TISSUES OF THE BODY. 



327 



0'0322 to 0'0751 mm. Some isolated bulbs may attain, however, 

 much greater dimensions, and twisted or indented forms are also met 

 with. 



The terminal bulb of Krause consists of a transparent nucleated envelope, 

 containing a soft, homogeneous, slightly lustrous substance. 



The nerves connected with it (c) undergo subdivision into branches 

 more or less frequently repeated (1*, 2). Thus from one primitive fibre 

 from 6 to ] terminal corpuscles may be 

 supplied. On entering the latter, the pri- 

 mitive fibres of medium size until there 

 (about 0'0046-0'0075 mm.) become imme- 

 ately still finer, constituting then the pale, 

 non-medullated end filament or axis cylin- 

 der (1 b). The latter is 0-0039-0-0029 

 mm. in thickness, passes through the axis 

 of the structure, and ends towards its upper 

 pole with a slight button -like swelling 

 about O0046 mm. across. 



The terminal bulbs of the human con- 

 junctiva (2) frequently present sinuosities 

 and twists on the primitive tube as it 

 is about to enter or has already entered the 

 former. These may be present to such an 

 extent as to form a regular convolution, 

 especially in the interior of the corpuscle. 

 Within the latter itself, or before its en- 

 trance, a splitting of the nerve tube may 

 take place ; beside which many varieties 

 are to be seen as regards its bearing. 



The number of these formations also 

 seems to vary considerably. In 1 Q /7/ of 

 the conjunctiva of the calf Krause noticed 

 1 3 terminal bulbs. 



Structures allied to the latter were also 

 met with by Krause in the glans clitoridis, 

 and in smaller number in the penis. 

 These " genital nerve-corpuscles " lie in the tissue of the mucosa at the 

 bases of the papillae of the mucous membrane. In size and form they 

 vary, some of them attaining a diameter (H439, or even 0*2001 mm. As 

 a characteristic of these genital nerve-corpuscles, constrictions may be 

 mentioned which occur in varying number on the surface, and com- 

 municate to the whole a mulberry-like appearance. They appear to be 

 the recipients of sexual sensation, for which reason finger proposes giving 

 them the name of " sensual corpuscles " (Wollustkbrperchen). 



The same observer has described another kind of structure similar 

 to the end-bulbs, as present in the racemose glands of mammalia. These, 

 the " end capsules of the gland nerves, 1 ' have a somewhat elliptical form, 

 and consist of a number of concentrically laminated membranes, from 

 four to eight of which may be observed in each, and which are studded 

 with numerous nuclei. In the interior is to be seen the minute cylin- 

 drical end-bulb, which is not unfrequently of sigmoid figure, and whose 

 axis is occupied by an almost immeasurably fine lustrous terminal fibre. 

 The latter springs from a dark-edged nerve tube. 

 22 



Fig. 314. Terminal bulb. 1. From the 

 conjunctiva of a calf. 2. From that 

 of a human being, a, Bulb ; c, nerve 

 fibre ending in (1) an axis cylinder (b). 



