452 The Islands of Langerhans in the Human Embryo 
efferent vessels. In those islands still connected with the acinus, a vessel 
does not accompany the connecting process of cells. By following an is- 
land through a series of sections, from four to seven branches, without 
definite arrangement however, may be seen entering from the periphery. 
The vessels at the periphery anastomose freely and form a network much 
richer than that about a glandular structure of equal size. _ At this period 
the cells between the capillary network of the island assume a definite ar- 
rangement in columns or rows. 
If the development here described is compared with that observed by 
Laguesse and by Renaut, an agreement is found only in regard to the 
method of primary differentiation. 'These early investigators failed to 
observe the stage of the process in which the solid column of cells con- 
nects the island with its acinus and therefore failed to note the gradual 
separation leading to final isolation of the island. 
The changes just described represent the last important phases in the 
differentiation of the islands. In the period represented by preparations 
11, 12, 13, and 14, the increase in size, the progressive vascularization, 
and the appearance of a fine reticulum along the vessels may be studied. 
Occasionally an island may be seen in continuity with its acinus, but this 
appearance is now unusual. In preparations 13, 14, 15, 16, 17, and 18, 
the glandular elements may be seen gradually surrounding the islands, 
while in preparations 19, 20, and 21 this process is completed and the. 
island is seen in the center of its acinus, the position it occupies in the 
pancreas of the adult. 
A number of specimens of the pancreas of children born dead during 
the last month of pregnancy and at term, as well as of infants surviving 
a few hours or days, have been examined. Except for slight differences in 
the amount of granulation of their cells, the islands appear identical with 
those of the adult. Specimens of this period, the blood-vessels of which 
are injected with carmine, show the extraordinary vascularity first de- 
scribed by Kiihne and Lea (17), but which is not more prominent than 
may be seen in the adult pancreas. 
Syphilitic Pancreatitis of the New-born.—Confirmatory evidence of the 
development above described has been furnished by a study of the changes 
occurring in that pancreas in congenital syphilis. This condition, first 
accurately described by Birch-Hirschfeld, consists of extensive sclerosis of 
the pancreas with simple atrophy of the glandular structures. The 
atrophy in the advanced stages is so extreme that the larger ducts, the 
islands, and a few fragrants only of glandular tissue remain. 
The persistence of the islands in contrast to the extensive atrophy of 
the glandular structure is a striking feature of this lesion. In Birch- 
