628 



LACTATION. 



[CHAP. XLIV. 



Fig. 297. 



Henle describes muscular fibres in these ducts ; but Kolliker and 

 most other anatomists have failed to detect them. We have searched 

 for them carefully, but with no better success. 



The blood-vessels are very numerous, and their finer branches 

 ramify around the terminal follicles of the gland. 



The absorbents have been injected by Sir Astley Cooper, who 

 describes a superficial set beneath the skin, and a deeper set of 

 trunks which penetrate into the substance of the gland, and form 

 a plexus of great beauty in the interior. 



In the male, the lacteal glands exist only in a very rudimentary 



condition; but their structure is 

 precisely similar to those of the fe- 

 male, as Sir Astley Cooper demon- 

 strated. In a few very rare instances, 

 they have been unusually developed ; 

 and instances are even on record, 

 where milk has been secreted by the 

 lacteal gland of the male ; indeed it 

 has been related, by Humboldt, that 

 the infant has been nourished by 

 the male parent after the death of 

 the female. 



The lacteal glands are developed 

 like other glands connected with the 

 In the fourth or fifth month, 

 to the observations of 

 Langer and JColliker, a papillary projection of the mucous layer 

 jfy. 298. f the epidermis occurs. This increases in size; 

 and, by the sixth or seventh month, throws off a 

 o number of offsets, from which the lobes of the 

 ooo* &l an d are gradually formed. 



O0 Milk is white and opaque, from the presence of 

 Q numerous oil-globules. Besides these, which are 



held in suspension, and are insoluble, milk contains 

 numerous nutritious substances which exist dis- 

 After it has been allowed to 



Lacteal gland of a newly-born child. The . . 

 rudimentary follicles are well shown. After Skill. 

 Langer. , . 



according 



a. Colostrum corpus- 



cies. b. Milk globules, solved in the fluid. 



In the lower part of the 



figure, two are seen run- stand for some time, the oil- globules rise to the 



ning together, in conse- , 



quence of the investing surface, by reason of their lightness, forming the 



membrane having been * 



dissolved. Magnified Cream. 



about 215 diameters. -n/r-n 111 i . 11 



Milk usually does not obtain its normal charac- 

 ters until three or four days after delivery. The first proportion, 

 which is secreted before parturition, is thinner, and contains but a 



