THE MARCHING OF THE LARVA OF THE MAIA MOTH. 265 



upon the thread alone in following the path of those ahead. I 

 next removed the thread, and then dipping a finger in water, 

 rubbed it rapidly a number of times across the path and then 

 wiped the place dry. When the first caterpillar reached this 

 spot, he halted, and for three minutes remained at the same place, 

 raising the anterior part of the body in the air acting the same as 

 if the leader had been removed. At the end of this time he 

 started forward following, as near as I could judge, the original 

 path. 



The following few experiments should have been made with 

 the food plant of the caterpillar, but this being unobtainable at 

 the time of the year when the caterpillars were hatching in my 

 room, the leaf of the geranium, Pelargonium, which was easily 

 obtained and possessed quite an odor, was used. 



1 . A small piece of the leaf was placed 5 mm. away from a 

 small group which had been quiet for two or three hours ; the 

 caterpillars became at once restless and in two minutes, three 

 had moved over and touched the leaf. 



2. A small piece of the leaf was placed 5 mm. away from the 

 leading caterpillars in a line ; they became at once restless and 

 " broke rank " ; in four minutes two (not the leader) had reached 

 the leaf. 



3. A piece of leaf was placed 15 mm. from a group, nothing 

 happened ; the leaf was moved to 10 mm. and left for ten min- 

 utes, nothing occured ; moved to distance of 5 mm. from cater- 

 pillars and all still remained quiet. I now moved the leaf to 3 

 mm. away, one immediately came out, touched the leaf and 

 returned to its original position, in thirty seconds another came 

 out, touched the leaf and returned. 



4. A piece of leaf was placed 5 mm. from group, two came 

 out, touched it and returned. 



ZOOLOGICAL LABORATORY, UNIVERSITY OF WISCONSIN, 

 Madison, February, 1904. 



