316 JAMES W. McCOLLOCH AND H. YUASA 



TABLE VI 



Maximum and Minimum Rates of Migration of Larvae Hatched 

 from Eggs Laid in Inverted Position 



Part 1. — Maximum and minimum average rates of migration and distance trav- 

 eled at these rates. 



Entire Journey Upward Journey Downward Journey 



Average Average Average 



time time time 



required required required 



to move Distance to move Distance to move Distance 



1 mm. traveled 1 mm. traveled 1 mm. traveled 



Larvae that got down into sheath — 



No. 208-1 Max 24 sec. 294 mm. ? 139 mm. ? 155 mm. 



No. 64-2 Min 654 sec. 132 mm. 389 sec. 37 mm. 757 sec. 95 mm. 



Larvae that died on leaf — 



No. 221-1 Max 41 sec. 131mm. ? 44 mm. ? 87 mm. 



No. 226-1 Min 2769 sec. 26 mm. ? 26 mm. 



Part 2.— Maximum and minimum distances and average rates of migration used 

 to travel these distances: 



Larvae that got down into sheath — 



No. 208-1 Max 24 sec. 294 mm. ? 139 mm. ? 155 mm. 



No. 70-1 Min 72 sec. 100 mm. ? 20 mm. ? 80 mm. 



Larvae that died on leaf — ■ 



No. 217-3 Max 46 sec. 158 mm. ? 98 mm. ? 60 mm. 



No. 236-1 Min 300 sec. 12 mm. 300 sec. 12 mm. 



According to Table IV, which records the behavior of 12 

 selected individuals which came from eggs laid in inverted posi- 

 tion, there is absolutely no correlation of any sort between either 

 the maximum or minimum speed and distance or maximum or 

 minimum distance and speed. But Tables V and VI indicate 

 that there seems to exist, so far as these particular individuals 

 are concerned (although the same conditions apparently hold 

 true in a number of other cases) certain correlations between the 

 two items under consideration. The larvae which moved fastest 

 traveled longer distances than those that moved slowest, and the 

 larvae that traveled the longest distances moved faster than those 

 that traveled the shortest distances. The rate of migration either 

 on the upward or downward course, or on the upper or the 

 lower surface of the leaf does not seem to be affected to any 

 marked extent by the degree of inclination of the leaf. The 

 leaf may have an inclination of anywhere between zero and 

 90 degrees, but the larvae seem to be able to move with equal 

 facility in either direction. Acceleration or retardation, if any, 



