350 The Histogenesis of the Adrenal in the Pig 
concluded that the anlage of the cortex is derived from the peritoneum. 
Like Gottschau, he holds that the cortex and medulla are derived from 
the same source. 
O. Hertwig* teaches that the cortex is derived from tubules of the 
Wolffian body, processes from which grow dorsalward and surround 
portions of the sympathetic ganglia, which in their turn produce the 
medulla. 
Minot * holds that in man the anlage is laid down as a whole by the 
mesenchyme, the cells composing it afterwards undergoing differentia- 
tion into cortex and medulla. 
O. Schultze,’ while rather avoiding a general discussion of the sub- 
ject, affirms emphatically that in Vespertilio murinus the anlage of the 
adrenal is laid down in toto as a portion of the sympathetic ganglia, to 
be differentiated subsequently into cortex and medulla. 
The citations above have been introduced merely to illustrate the 
prevalent diversity of opinion. Anything like an adequate review of 
the literature would be forcign to the purpose of this paper, and a com- 
plete bibliography may be found in the publication of Aichel presently 
to be mentioned; but some of the work which marks the recent revival 
of interest in the adrenal requires more extended reference. 
Minot‘ accepts the mesenchyme as the source of the adrenal, and 
points out that the cells from the mesothelium collect near the inferior 
vena cava and the transferse septum to form the mesenchymal anlage. 
He believes, however, that this is not a special process, as Janosik 
thought, but that “the genetic relation of the whole mesenchyma to 
mesothelium renders it unnecessary to assume a special relation for a 
single mesenchymal organ.” He applies the same criticism to observa- 
tions indicating the mesothelium of the nephrotomes as the source of 
the adrenal anlage. 
As to the medulla Minot says: ‘“ That both the cortex and the me- 
dulla of the adult organ are formed in man from the mesenchymal 
cells, as Gottschau showed was the case in several mammals, is, I think, 
beyond question.” If the sympathetic unites with the mesenchymal 
anlage, it disappears in the course of development. For: “ By a con- 
siderable series of observations on the suprarenal capsules of human 
4Lehrbuch der Entwicklungsgeschichte des Menschen und der Wirbelthiere, Jena, 
1897. 
5Human Embryology, New York, 1897. 
6 Grundriss der Entwicklungsgeschichte des Menschen und der Siugethiere, Leipz., 
1897. 
7Op. cit., pp. 485-489. 
