134 GEO. S. HUNTINGTON 
presentation the homologization of the right eparterial bronchus 
with the ascending branch from the first left ventral hyparterial 
bronchus to the cranial pole of the left upper lobe. 
Finally Narath (31, 33) in a preliminary paper, published in 
1892, and in his large monograph (’01) became the chief and 
very enthusiastic exponent of the theory, offering in support of 
the same many additional comparative anatomical and onto- 
genetic observations, and an invaluable record and classifica- 
tion of bronchial variants. If in the following pages I appear 
as an antagonist to Narath, it is solely because many years of 
careful study given to the problem have convinced me that the 
deductions which he has drawn from his material, and the theo- 
retical conclusions based thereon, are erroneous. These I feel 
obliged to oppose. But I do this with a full realization and 
appreciation of the permanent value of Narath’s contribution. 
His monograph is a veritable storehouse of new morphological 
observations and records, splendidly arranged, clearly expressed 
and beautifully illustrated. It will remain for all time as one 
of the classical records marking the progress of anatomical 
science. 
As elaborated by Narath, the migrating theory of bronchial 
evolution, if followed to its logical conclusion, assumes a simple 
hypothetical phyletic ground-plan of bronchial organization. 
The stembronchus gives origin solely to a single ventro-laterally 
directed series of primary bronchial derivatives. Lateral 
branches of these alter their primitive position in the bronchial 
system in the course of evolution by becoming ‘split off’ from 
their original parent stems, and transfer themselves through a 
process of ‘wandering’ or ‘migration’ to the stembronchus, ob- 
taining thus new and independent points of origin directly from 
the same. In the words of the theory, as stated: by Narath, 
the original ventro-lateral branch of the stembronchus has 
‘ceded’ (‘abgegeben’) one of its lateral derivatives to the same. 
The evolutionary record of the dominant mammalian type 
(Aeby’s type II*) would read as follows: 
The bronchus destined eventually to supply the upper lobe 
of a fully developed right lung makes its first appearance as a 
