504 
ANNE M. LUTZ 
Cold Spring Harbor studies and to work out the majority of the 
details of special cell-study connected with these investigations 
(exclusive of chromosome counts) in consultation with Professor V. 
Gregoire at the University of Louvain during the year 1911-12. It 
is with the most profound gratitude that I express my appreciation 
of the help received from Professor Gregoire in this work — a portion 
of which is represented by these three communications; of his untiring 
devotion of time and thought from October, 191 1, until August, 1914, 
to the correct interpretation of recorded observations; to the veri- 
fication of numerous microscopical details of the work; and to the 
solution of many problematical questions which have arisen in con- 
nection with these studies. The chromosome count of every type 
mentioned by the writer in this and the two reports to follow, was 
carefully verified by Professor Gregoire, especial attention having been 
given to those which for any reason might be questioned. It is reas- 
onably certain, therefore, that the identification of the Cold Spring 
Harbor forms and the chromosome numbers to be announced in the 
three papers of the series, are correct. 
To Professor J. C. Arthur, Professor Stanley M. Coulter and Mr. 
George N. Hoffer, I am most deeply indebted for innumerable cour- 
tesies and many privileges enjoyed in the botanical laboratories of 
Purdue University during the past three years. 
I wish also to express my gratitude to Professor H. E. Crampton 
for privileges accorded to me, through his courtesy, at the American 
Museum of Natural History; to Dr. F. E. Lutz and to Professor B. M. 
Davis for numerous favors and accommodations; to Professor H. H. 
Bartlett for generously providing me with unpublished data relating 
to certain new and interesting forms which he has recently discovered, 
and for his kindness in giving me permission to quote his statements 
concerning them in these communications. 
The primary object of these three papers is to discuss, in the light 
of the Cold Spring Harbor and Louvain studies of somatic chromosome 
number in Oenothera Lamarckiana and its derivatives, certain theories 
and conclusions which Gates has announced from time to time, and 
which Gates and Miss Thomas have based upon the results of their 
investigations. Partly for this reason, but chiefly because of limi- 
tations of space, all but a few of the more important mutants reported 
will be described very briefly, or not at all, these descriptions being 
reserved for a later publication. With the exception of a few forms 
