214 
BULLETIN OF THE BUREAU OF FISHERIES 
ACKNOWLEDGMENTS 
I wish to acknowledge the assistance and cooperation of the members of the staff 
of the Wisconsin Geological and Natural History Survey. Dr. Chancey Juday 
offered much valuable advice, particularly in the selection of lakes for study, and sup- 
plied needed limnological information. Dr. Edward Schneberger was completely 
in charge of the 1932 collecting operations. 
Dr. John Van Oosten, in charge of the Great Lakes fishery investigations of the 
Bureau of Fisheries, gave much valuable advice (both as to field procedure and 
methods of analysis of data) during the execution of this work, and gave his assist- 
ance freely in the interpretation of difficult scales. Dr. Van Oosten also made a 
critical examination of the manuscript. 
Dr. Carl L. Hubbs, curator of fishes in the Museum of Zoology of the University 
of Michigan, read the original manuscript and offered valuable suggestions for its 
improvement. 
Harry C. Carver, professor of mathematics and insurance in the University of 
Michigan, read the section of the manuscript on the relationship between length 
and weight. 
Dr. Peter Okkelberg, secretary of the Graduate School of the University of 
Michigan, checked the accuracy of my translation of portions of Huitfeldt-Kaas’ (1917) 
publication. The reference to Olofsson’s (1932) paper is based on an abstract pre- 
pared by ft. W. Eschmeyer of the Michigan Institute for Fisheries Research. 
The determination of age and the calculation of growth of the 1928 collection 
of the Trout Lake cisco are entirely the work of Dr. Stillman Wright, formerly of the 
Bureau of Fisheries. 
MATERIALS 
The investigation of age and growth has been based upon the determination of 
ages for 3,882 specimens and the calculation of growth for 3,694 specimens. Speci- 
mens other than those whose ages were determined have been used incidentally for 
other purposes such as the study of vertical distribution of the cisco and the density 
of population. Koelz (1931) described material from each of the six lakes whose popu- 
lations are considered in this study. According to Koelz 3 subspecies of Leucichthys 
artedi are represented in these 6 populations. Clear Lake is the type locality for 
L. artedi clarensis Koelz. The same form is accredited to Muskellunge, Silver, and 
Allequash Lakes. Koelz described the Trout Lake cisco as L. artedi clemensi Koelz, 
and the form occurring in Tomahawk Lake as L. artedi wagneri Koelz. However, 
Hile (MS.) in a paper now in press has demonstrated that the ciscoes of these lakes 
at present are not susceptible of division into subspecies, but should be considered 
merely as populations of the species, L. artedi. 
Table 2 lists the locality and year of capture of the ciscoes used in the life-history 
studies. The 1931 material includes 658 preserved specimens collected for a mor- 
phometric study to appear in a later publication, while all the 1932 Muskellunge 
Lake specimens and 95 of the 1932 Clear Lake specimens were preserved. 
