THE FEEDING REACTIONS OF AMBYSTOMA 
TIGRINUM (GREEN) 
By ALBERT Kuntz and José Zozaya 
St. Louis University School of Medicine 
The following experimental study is based on a large number 
of late larvae and young adults of Ambystoma tigrinum. The 
majority of the animals used were taken in an upland kettle- 
hole in which they were present in great abundance. They were 
relatively small, measuring 8 to 10 em. in length and weighing 
10 to 12 grams. The majority of the animals taken in this 
habitat were late larvae. The rest were young adults many of 
which had scarcely completed their metamorphosis. The other 
animals used were taken in a larger kettle-hole lying somewhat 
lower. The species was less abundant in this habitat, and the 
individuals were much larger, measuring 18 to 20 em. in length 
and weighing approximately 40 grams. The majority of these 
animals also were late larvae, the rest were young adults which 
had scarcely completed their metamorphosis. All the animals 
used were collected during the latter half of July and August. 
Many of the animals taken as larvae completed their metamor- 
phosis while under observation in the laboratory. 
This study was carried out at the Iowa Lakeside Laboratory 
during the season of 1920. The writers desire to acknowledge 
their indebtedness to Prof. R. B. Wylie, Director, for the op- 
portunity of working at the Laboratory and for his interest in 
furthering the work. 
Larvae. All the larvae which had not yet entered the final 
phase of their metamorphosis when they were taken were well 
fed and manifested little or no interest in food which was pre- 
sented to them. Some would accept and eat somewhat reluc- 
tantly bits of meat which were held before them, others would 
pay no attention to food. After being kept in an aquarium 
without food for several days they manifested hunger by seiz- 
ing and eating bits of meat which were held before them, or 
Contributions from the Iowa Lakeside Laboratory, No. 53 
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