150 THE ENTOMOLOGIST. 



the caterpillars of the fir-tree arrow-tail moth. I cannot well 

 express with words how delighted we were, and the more so 

 as we supposed that this insect did not dwell at all in this 

 country, but, as we knew already, in Germany. We found a 

 small caterpillar on a fir-leaf, and observing that it had a 

 horn on the tail we could come to no other conclusion but 

 that it must be the caterpillar of the fir-tree arrow-tail moth, 

 although somewhat pale; the smallness of the caterpillar 

 showed that it had not escaped from the egg many hours. 

 Through this new discovery, uncommonly encouraged, we 

 became very zealous in searching for this insect, and found 

 several of its eggs, but these were, to our sorrow, impregnated 

 with strange eggs, and consequently perished : another new 

 discovery, — a very strange phenomenon, — at which we won- 

 dered not a little ; for that the caterpillars should be impreg- 

 nated with eggs of wasps and flies, and thus become destroyed, 

 was a well-known fact, but that the eggs also of some flies 

 should have to submit to this lot seemed to us paradoxical 

 and incomprehensible. I shall, further on, speak more on 

 this subject, but must now consider the history of this insect. 

 After some search we found other two of these caterpillars, 

 the one much greater than the first and probably already 

 twice changed, the other nearly full grown. These three cater- 

 pillars having been fed carefully with the fir-leaf, and having 

 grown large, we saw, to our great delight, that towards the 

 end of September two of them crept into the earth and 

 became yjupse, but the third died still young. The two pupse 

 remained all winter in the ground, and on the 6th July 

 following there came out of the one a beautiful and lively 

 moth, but the other brought forth a so-called bacon-eater 

 (being a certain kind of wasp), with whose eggs this cater- 

 pillar had been impregnated. 



§ 2. — The complete house-holding of this insect, from the 

 very egg to the last or flying state, was now sufficiently 

 known to us, except that we had not yet seen any undamaged 

 eggs; but in the year 1767, on the 12lh July, we found two 

 good eggs, out of which the caterpillars came on the 21st of 

 the same month, which we brought up until they were 

 almost full grown, when, however, they died. But in the 

 following year, 2nd July, a great and eminent amateur gave 

 us a still better opportunity of observing the house-holding 



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