ZOOLOGY. 481 
Amherst, Mass. with the query “What are the New England lo- 
calities of this rare plant ?”? During 1859-60 I found it in the 
vicinity of Bangor, Me., on land newly cleared and burnt over, 
growing as abundantly as erechthites or any of the ‘fire weeds,” 
many acres being entirely covered with it. 
Making a trip subsequently to Mt. Katahdin, nearly one hun- 
dred miles north from Bangor, I found it abundantly, at intervals, 
in clearings, all along the route. But I have never found it else- 
where in New England.—J. W. CHICKERING. 
[It is known to occur in Brunswick, Maine. — Eprrors. } 
Tuer Uses AND ORIGIN or THE ARRANGEMENTS oF LEAVES IN 
Piants.—A paper by Chauncey Wright, with the above caption, 
appears in the last part (vol. ix, part ii) of the Memoirs of the 
American Academy of Arts and Sciences. It is a philosophical 
and exceedingly interesting discussion of the subject, and we sha 
endeavor to bring it te the notice of our readers in a subsequent 
number. 
ZOOLOGY. 
SPONTANEOUS Drviston IN StarrisHes.— Mr. C. Lütken, of Co- 
penhagen, so well known for his important researches on the nat- 
ural history of certain groups of the Echinoderms, has recently 
laid before the Royal Academy of Copenhagen the results of some 
very interesting and valuable investigations on the spontaneous 
division of the starfishes and brittle-stars. Professor Verrill has 
recently described a new genus of brittle-star ( Ophiothela), all the 
known Species of which possess a number of arms greater or less 
than five, generally six, and in some few instances three or two; 
very rarely indeed does the normal number of five make its appear- 
ance. Lütken describes a new species of this genus (O. isidicola) 
on a certain number of specimens of which he finds six nearly equal 
arms, but in the majority of these specimens there is a marked 
difference between the three arms on one side of the body and the 
three arms on the other; in another set the difference is still more 
marked, the one set of three arms being quite small and the other 
of the ordinary size. In others, again, this difference is extended 
to the disk itself, and it looks as if it had been cut in two by a 
knife. In all these cases there can be little doubt that these 
“ppearances result from a primary division and then a regeneration 
AMER. NATURALIST, VOL. VII. 
