308 JAMES W. McCOLLOCH AND H. YUASA 



her eggs with the head end pointing downwards towards the 

 main stem, so that when the tiny larva emerges it is started 

 from its infancy in the right direction on its journey downwards, 

 and, guided by the longitudinal striae of the leaves, it reaches 

 the stem, round which the leaf -sheath is closely wrapped, but 

 not too close to prevent the larva forcing its way; until, after 

 some four hours' steady travelling (during which time it has 

 covered only the small distance of two or three inches) , it reaches 

 the base of the sheath." He also made some observations on the 

 hatching of eggs that were laid " the wrong way, with the heads 

 towards the tip of the leaf." In this case, " the larvae worked 

 their way to the tip of the leaf, where some of them managed 

 to cross the edge and get on to the back or under side, and com- 

 menced their tremendous journey of four or six inches ! some 

 arriving at their destination at the next joint below the one they 

 would have occupied had the female laid her eggs on the inside 

 of the upright leaf." 



Garman (1903, pp. 221-222) reports that " the eggs hatch in 

 a week or less (three days in one instance observed), according 

 to temperature, and begin their rather laborious journey to the 

 leaf-sheath, during which they find even an egg or egg-shell an 

 obstruction to be surmounted with difficulty. From the slow- 

 ness of their progress the trip requires hours of time, and except- 

 ing as their minute size protects them, they are completely at 

 the mercy of enemies. No doubt many of them are lost at this 

 period of their lives." The same author states (p. 221) that 

 when the eggs are laid on the lower surface of the leaf ' the 

 helpless young must have difficulty in finding their way between 

 the leaf-sheath and the stem, with a good chance of perishing 

 before this is accomplished, since it is their habit to follow 

 closely the grooves in which they hatch down to the junction of 

 blade with stem." 



Gossard and Houser (1906, p. 4) report that the young larva 

 " starts at once down the leaf, following the groove or crease 

 in which it hatched, or an adjacent one, until it reaches the 

 base; from this point it burrows between the leaf sheath and 

 the stalk until it reaches the foot of the culm, . . . While 

 on this downward journey, which may occupy several hours, the 

 young larva is easily deflected from its course by dirt particles 

 or mechanical obstructions, and may lose its hold and fall to 



