The Sacred Beetle and Others 



permanent appendage? The evolution of 

 the nymph is swift; the insect is perfect in a 

 few weeks. Could it not be that, though 

 this brief space suffices to promote the 

 maturity of the horns on the forehead, the 

 thoracic horn requires a longer time to 

 ripen? Let us prolong the nymphal period 

 artificially and give the germ time to develop. 

 It seems to me that a decrease of tempera- 

 ture, moderated and maintained for some 

 weeks, for months if necessary, should be 

 capable of bringing about this result, by de- 

 laying the progress of the evolution. Then, 

 with a gentle slowness, favourable to delicate 

 formations, the promised organ will crystal- 

 lize, so to speak, and become the spear 

 promised by appearances. 



The experiment attracted me. I was un- 

 able to undertake it for lack of the means 

 whereby to produce a cold, even temperature 

 over a long time. What should I have 

 obtained if my penury had not made me 

 abandon the enterprise? A retarding of the 

 progress of the metamorphosis, but nothing 

 more, apparently. The horn on the corselet 

 would have persisted in its sterility and, 

 sooner or later, would have disappeared. 



I have reasons for my conviction. The 

 abode of the Onthophagus engaged on his 

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