2 



K. MITSUKUKI. 



"body becomes contracted and rigid. In short they enter an inactive 

 state which might be called the " summer sleep." They are in this 

 condition all through the hot summer months and crawl out only when 

 the cooler weather approaches. 



D uring thei' abstinence from food, the alimentary canal of these 

 holothurians becomes reduced into a very slender almost thread-like 

 tube without any food-stuff or sand-grains in it. On October 4, 1893, 

 I examined at Kanagawa four individuals of second year and three 

 adult individuals of the third year and upwards. Of the former : 



t had its alimentary canal slender and utterly empty. 



2 had their alimentary canal tolerably full of sand and food. 



I had its alimentary canal abundantly full of sand and food. 

 Of the older lot : 



1 had a very small; quantity of sand in its alimentary canal. 



2 had their alimentary canal slender and utterly empty. 



As there were thus on this day some individuals with their digestive 

 tract still slender and empty, and others with it full of sand-grains (and 

 food stuff), the inference is justified that these holothurians were just 

 then crawling out of their summer hiding place. As some had already 

 been seen in the Tokyo market before this date, it is reasonable to 

 conclude that the crawling out of the holothurian takes place in the 

 neighborhood of Tokyo in the latter part of September and the earlier 

 part of October. It seems also probable that older individuals seem to 

 penetrate into dark crevices and holes much more deeply and also at 

 greater depths of the sea than younger ones which stay, so to speak 

 less in shade and that younger ones thus come out earlier than the 

 older ones. 



As soon as the holothurian comes out of its hiding plac 

 recovers its former activity, begins to take food, and its alii, 

 canal regains the original calibre. The reproductive tubes are at 

 time even in adult individuals very short being only about 2 cm. lo. g 

 and very slender with only a few branches. These, however, begin to 

 lengthen rapidly. On Dec. 2 (1893) when I dissected four adult 



