8 MUSEUM OF COMPARATIVE ZOOLOGY. [Feb. 
annual courses of lectures have been delivered there by myself, 
except when illness or necessary absence have occasionally 
interrupted them; while from time to time other courses, and 
very valuable ones, have been given by the gentlemen connected 
with the Museum. We have always had, also, a certain num- 
ber of students pursuing special studies in the laboratories. 
This has been well, as far as it went; but the case is now very 
different. With very able men as assistants ;.with a distribu- 
tion of labor which makes the work of the Museum itself easier, 
it is now possible to arrange a very complete system of general 
and special instruction. The programme for the current year 
embraces seven courses of lectures, and practical instruction, 
- covering nearly the whole range of natural history. We hope 
to make it more comprehensive in proportion as some of those 
mature investigators who can act both as scientific assistants 
and as lecturers are drawn into our ranks. 
During the past winter, the lectures have consisted of an able 
course from Mr. Perry, on the geology of Lake Champlain, 
including a description of the geological formation of Vermont, 
and especially a critical discussion of the controversy concern- 
ing the Taconic system. Mr. Shaler has also given a full and 
interesting course on paleontology, illustrating chiefly the gra- 
dation of organized beings throughout the series of geological 
formations. J have myself given a course on the natural his- 
tory of Radiates. Of the latter I would say a few words. 
Since it may not be in my power to publish for some time the 
results upon which this course was founded, I wish to submit 
them summarily here, though they do not perhaps properly — 
belong in this very general report of the Museum affairs. The 
object of this course was to show the strict homology pervading 
the structure of all Radiates, including the Echinoderms as 
well as the Polyps and Acalephs, or the so-called Coelenterata. 
This identity of structure being proved, the division of the — 
Radiates into two distinct types, now adopted by most zodl- 
ogists, becomes unnatural. The argument rests upon facts, for 
it can be clearly shown that the chambers of the Polyps, sep- 
arated by their radiating partitions, are homologically identical 
with the radiating tubes of the Acalephs, and with the ambu- 
lacral system of the Echinoderms. These three classes form, 
structurally speaking, one and the same type. Moreover, these 
