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diagonal course in entering the bark, before asauming the typical 

 longitudinal direction, and though usually, do not always, lie close to 

 the wood. Though much smaller in diameter than those of S. destructor, 

 they are nearly as long, and I have seen one four inches in length. The 

 number of eggs laid in a burrow is about a hundred; they are deposited 

 behind a continuous layer of frass, which does not encroach on either 

 the floor or roof. The period of oviposition is about a week later than 

 that of 8. destructor. I have several times found a male and a female 

 beetle in the burrow when it was less than half-an-inch long, and before 

 any eggs had been laid, but never after that period. The larvae form 

 their hybernacula in the thickness of the bark, hardly ever in the wood. 

 8. multistriatus is a much less hardy insect than 8. destructor, and of all 

 the species of Scolytus I had in captivity last winter, multistriatus is 

 the only species of which I failed to rear even a single specimen. 

 Moreover, I have observed that in a state of nature, but a compara- 

 tively small proportion arrive at maturity, which to some extent accounts 

 for its rarity. I have never observed any indication of autumnal 

 specimens. 



4. Scolyttjs petjni, Batz. I have met with this species (usually 

 considered a rare one) in apple and pear trees, and have found its aban- 

 doned burrows in apricot. It is said to affect various fruit trees. The 

 apple tree in which I have found it had been slowly dying, successive 

 strips of the bark from top to bottom of the tree had died year after 

 year, and it was in the last strip that 8. pruni had burrowed and com- 

 pleted the death of the tree ; I have met with traces of its having more 

 sparingly attacked the previous strips. 



Unlike the other species of the genus which make nearly uniformly 

 cylindrical burrows (there is often a trace of a diverticulum near the 

 entrance of 8. destructor's burrow), the first part of the burrow of 8. 

 pruni is a nearly square chamber, as if two burrows had for so far been 

 placed side by side. I have found the male beetle in this cavity in bur- 

 rows little more than begun, and in others nearly two inches long, and 

 have no doubt that it is formed by the male beetle, who eats the reserved 

 material as food : in none of the other species have I found the male 

 residing in the burrow for more than a very brief period. 



The remainder of the burrow is from two to four inches long, and 

 slightly encroaches on the wood. The eggs are covered by a layer of 

 fine frass, which usually forms merely a series of detached patches filling 

 up the egg cavities to the level of the wall of the gallery. The larvae 

 almost invariably bury themselves in the wood for hybernation, and the 



