The Ohio Naturalist, 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume Ml. NOVEMBER. 1902. No. 1. 
TABLE OF CONTENTS 
I.andacre— Muscular nnd Skeletal Elements of Passalus Cornutus 299 
Burr— Ohio Plants with Dissected Leaves 314 
Kiddle — Algae from Sandusky Bay 317 
Schaffner— The Maximum Height of Plants 319 
Landacre— On a Visual Area in I.ainpsida Veutricosus 320 
Jennings— Meeting of Biological Club 322 
MUSCULAR AND SKELETAL ELEMENTS OF 
PASSALUS CORNUTUS. 
F. L. Landacre. 
The present paper on the muscular and skeletal elements of 
Passalus cornutus was begun with a view to determining what 
changes had arisen in the muscular system in connection with the 
burrowing habits of the animal. It was found in the course of 
the study that there was an almost complete atrophy of the mus- 
cles concerned in flight and a marked hypertrophy of the muscles 
of the legs ; and that with these changes had arisen certain modi- 
fications in the hard parts to which these muscles are attached. 
These changes in the hard parts were not so numerous or so 
radical as to justify the rather extended description of the skele- 
ton. which had been given, if it were not for the fact that the two 
systems are so intimately related and the changes in the one so 
dependent upon those in the other that constant reference would 
have to be made to the skeleton. This would be confusing to a 
reader not entirely familiar with the hard parts. 
The study of these two systems led to an investigation of the 
habits of the insect, especially those concerned in distribution and 
reproduction. 
Passalus is a large black beetle of common occurrence in de- 
caying logs and stumps which it assists materially in destroying. 
It can easily be identified by its large size, great strength, sluggish 
movements and longitudinally striated wing covers. It has a pe- 
culiar habit of stridulating when disturbed. 
It can be secured in great abundance at all times of the year 
and is easily kept in the laboratory for observation if it is supplied 
with an abundance of decaying wood. Specimens for dissection 
