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The Rhini")ceros beetle probablj' lives long as a mature insect; 

 but observations are wanting. Without food Ghosh found it to live for 

 three weeks. If dissected, very few eggs can be found in the female 

 at any one time, and Ghosh observed that they are laid, say, three on 

 one day, two on the next, two on the following day, and so on, each 

 ■egg apart from any other. 



But unless this slow egg-laying continues over a long period 

 how could one get the millions of grubs which were collected in 

 Samoa.' The eggs, Ghosh found, were laid at night. The grubs 

 hatched out after ten to twelve days, at the beginning of June. On 

 the twentieth of October, grubs from these same eggs appeared to 

 him to be full grown. Where Ghosh worked, a cold dry weather 

 sets-in, in October, and is followed by a hot dry weather lasting until 

 June. Ghosh's beetles made no progress during the cold dry 

 season, though they were not dormant. One beetle only survived it 

 and emerged on the fifth of May, having taken nearly twelve months 

 to complete its cycle. 



Yet it seems probable that in warmer damper countries such as 

 the Malay Peninsula, growth is continuous and the life-cycle short- 

 ■ened to fewer moths ; if this were not so we should find a greater 

 proportion of large full grown grubs than we do, and the writer has 

 some reason for thinking that six to seven months are enough fur the 

 beetle to pass from one generation to another : and again supposing 

 that four grubs were introduced into Samoa in 1909, two of each sex, 

 and that they matured and laid eggs, so large a supply as was 

 present in 1913 requires that each female should have deposited 

 considerably more than two hundred eggs, if the period of one 

 generation be twelve months; but if the period of one generation be 

 six months, fifty-four millions might be reared from two females 

 laying fifty eggs apiece. 



The grubs are blind, and very soft-skinned behind the head. 

 Five minutes exposure to sunlight kills them at maturity. They 

 have a breathing apparatus capable of being closed, which is an 

 adaptation for living in almost liquid decaying matter. Their demand 

 for moisture is very great. We can kill them easily by letting 

 them dry, and conversely w-e can greatly encourage them by supply- 

 ing to them damp coconut stems. Tliere is a no more mischievous 

 practice than that of lining the banks of a ditch or stream with 

 •coconut logs and every such place must be ruthlessly destroyed. 

 The practise of using coconut logs for bridges is only a little less 

 obnoxious, and should be stopped. The leaving of stumps in the 

 ground in dry places through dry weather is not obnoxious; but 

 the leaving of stumps in the ground in wet places and in wet 

 weather is ; and as sooner or later wet weather comes on the once 

 dry stump becomes damp enough for the beetle-grubs to grow in it. 

 The necessity for removing such stumps depends on the length of 

 time that they are likely to remain damp enough for the grubs — 

 whether it may be a period approaching their (apparently) six months 

 <:ourse of growth or less. 



