120°? The Development of the Lungs 
of the lateral bronchi, Narath has the support of Blisnianskaja, who 
argues if the “eparterial” is a dorsolateral bronchus, it is reasonable 
to suppose the remainder of the series are similarly derived. Neither 
of these authors, however, have followed the wandering step-by-step either 
of the eparterial or the dorsal branches on to the stem bronchus. They 
are, on the contrary, independent derivatives of the stem and, like the 
lateral series, are to be considered as a group of principal bronchi. 
Phylogenetically they are one of the most sharply differentiated groups 
of the stem. We have designated the dorsal series, D. 2, D. 3, D. 4, ete., 
to keep their numerals in harmony-with that of the larger lateral bronchi, 
although it is clear, of course, that our D. 2 is the first element of the 
dorsal series. 
VENTRAL BRONCHI. 
Because of their extreme variability, Aeby looked upon this group as 
accessory bronchi, which had their origin in the lateral series and subse- 
quently wandered to take up a position on the stem bronchus. Among 
this group he classifies the Bronchus cardiacus. These conclusions were 
obtained from the study of adult specimens, so Aeby brings no definite 
proof of their wandering. His does not mention them, while Willach, 
also without evidence, seems to accept Aeby’s view. They are, according 
to Robinson, a definite group of independent bronchi, which he terms 
ventral. Narath accepts the older view of Aeby, but like that author, 
his conclusions, with the exception of the infracardiac bronchus, are 
drawn from comparative study of corrosions of the adult lungs. More- 
over, even in the case of the Bronchus cardiacus, Narath acknowledges 
embryology brings no direct proof of a wandering in the sense of Aeby. 
d@Hardiviller clings to the expression accessory, although he regards this 
group, which he terms anterior bronchi as independent derivations of 
the stem bronchus. In the latter view he is supported by Nicholas and 
Dimitrova who, like Robinson, term them ventral branches of the stem. 
The results obtained from the pig indicate that the ventral bronchi are 
independent derivatives of the stem and do not form first on the lateral 
series and then secondarily become transplanted on to the main bronchus. 
VENTRAL Ep BRONCHUS CARDIACUS. 
This bronchus Aeby looked upon as the most important of the ventro- 
accessory group. Derived primarily from the second lateral bronchus, 
it takes its place upon the stem bronchus between it and L. 3. In many 
species it supplies a separate lobe, the Lobus infracardiacus instead of 
