Rit DEVELOPMENT OF THE ADHESIVE, ORGAN 
AND HEAD MESOBLAST OF AMIA= 
JAcoB REIGHARD AND JESSIE PHELPs. 
In 1895? it was noticed by one of us that, at a certain 
stage in its development, the adhesive organ of Amia con- 
sists of a pair of diverticula whose walls and lumina are 
continuous with the corresponding parts of the foregut. Two 
years later we undertook a study of the development of this 
organ in order to determine whether it originates from the 
entoblast, as indicated by this observation, or from the ecto- 
blast, as claimed by previous investigators of Amia, Aci- 
*From the Zoological Laboratory of the University of Michigan, Ann 
Achor, Mich. U.S: A. No. 116. 
*In 1895 I noticed the connection referred to in this paragraph between 
the adhesive organ of Amia and the corresponding parts of the foregut. 
Two years later Miss Phelps undertook, under my direction, to trace 
the complete history of this organ. When Miss Phelps’ work had been 
completed two brief preliminary notes were published (Phelps, 1899, 1900), 
but it seemed best, before final publication, to add the history of the head 
mesoblast in so far as this is related to the adhesive organ. For this 
part of the paper, as well as for the theoretical matter (see Reighard, 
1902), I am responsible. The publication of the paper has been from time 
to time postponed in the hope that it might follow the “Normentafel of 
Amia” the preparation of which had been begun. The Normentafel has 
been greatly delayed by my inability to use my eyes for microscopic work, 
and I do not now know when it may be completed. The recent appear- 
ance of a paper on “The Adhesive Organ of Amia” by Eycleshymer and 
Wilson (1908) makes desirable the immediate publication of the present 
more detailed study. It is printed as it was completed in July, 1900, with 
no attempt to consider literature which may have appeared since that 
time. The only additional matter in the body of the paper is that in the 
foot notes, and concerns the publication of Eycleshymer and Wilson above 
referred to, whose results are in several respects at variance with our own. 
Some titles have been added to the literature list—J. R. 
(469) 
