106 THE PINE DESTROYER. 



It SO frequently happens that a minute object is lost, simply by 

 removing the pocket lens for an instant to take up the pipette ; in 

 the above apparatus the lens remains in the position in which it 

 has been placed. 



The definition of these aplanatic lenses is excellent : the 

 lowest power has enough working distance to focus through all my 

 tanks, and the magnification (6 diam.) is sufficient to permit of the 

 identification cf all ordinary rotifers, and anything uncommon, or 

 new, is at once recognised. Such delicate creatures as the 

 Floscules^ which are all but invisible with the ordinary pocket lens, 

 are seen without difficulty, and the whole contents of the tank can 

 be ascertained with a great saving of time. 



I would also specially recommend these small window aquaria 

 to those not already acquainted with them, as affording the very 

 best means of examining pond water for microscopic life. 



ZTbe pine ©eetrO^er (Hylurgus pinlperda). 



By the Rev. Hilderic Friend, F.L.S., Carlisle. 



Plate IX. 



Introductory. 



IT was truly remarked by Curtis"^ early in the present century 

 that " although the oak and many other trees maintain mul- 

 titudes of insects, none appear to support more destructive 

 inhabitants than the Pines." Since these words were written, 

 many additions have been made to our knowledge of the parasites 

 and saprophytes which infest our healthy as well as our moribund 

 fir-trees, and with this increase of knowledge we have no warrant 

 for modifying the conclusion formerly arrived at. These "destruc- 

 tive inhabitants " are not confined to either the animal or the 

 vegetable kingdom, neither are they represented by one particular 

 order, family, or genus of plants or insects. Within recent years 

 much has been written about the fungoid parasites of the Pines, 



* British Entomology, Vol. III. (1826), Plate 104. 



