272 CATERPILLARS AND THEIR MOTHS 



of each tubercle, those on the four tubercles over the 

 head being black, the others white. When the larva 

 hatched, the red raised dots — for they were not more 

 than that — began to grow at once, the red color re- 

 maining in the tip of each, and the lower part having 

 almost no color at first. The growth was so rapid 

 that in five minutes after leaving the shells the long 

 thoracic tubercles or "horns" had their normal size 

 and shape, and the lateral spines had appeared. The 

 setse grew dark first, then the spines, then a pale red 

 color suffused the horn, as if it ran down from the 

 tip, which grew paler. 



The abdominal tubercles gained the normal color 

 first, in about fifteen minutes, and in an hour all the 

 tubercles, spines, feet, tips of props, and mouth-parts 

 had become black. 



The development of the long tubercles was very- 

 rapid and very interesting, and was watched in many 

 instances, each one giving exactly the same details in 

 the same order, though the caterpillars differed much 

 in the time they took to eat their way out of the shell, 

 some needing an hour, others over two hours. 



Observation of another set of eggs showed that the 

 color of the thoracic setsB varied, some larvae having 

 the setae all black before hatching, others having only 

 those of the first segment black, the others being 

 white. 



The little caterpillars were nearly a quarter of an 

 inch long, deep ocher-yellow in color, with black trans- 

 verse lines on the dorsum, except on the thoracic seg- 

 ments. The first segment had two prominent tubercles 

 and four small ones. The second and third segments 



