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PLANTS AS INSECT DESTEOYERS. 



By the Rev. W. W. Spicer, M.A., F.R.M.S. 



[Bead 10th July, 1877.] 



Being much attached to Botany, and, in a less degree perhaps to 

 Entomology, I have put together a few notes, bearing upon both 

 these sciences, and bringing before you one out of the many points, 

 at which the two great families of plants and insects cross each 

 other's paths— one, it must be added, in which the latter get 

 decidedly the worst of it. 



"We all know, to what an enormous extent insects are dependent 

 on plants for support. In the supply both of food and protection 

 Flora proves herself a veritable mother to her humble friends. But 

 there is a dark side in the character of even this gentle deity, whom 

 we are apt to associate with all that is cheerful and smiling ; and it 

 is astonishing to see in how many ways and under what different 

 aspects she puts forth her " insecticidal " functions. Directly or 

 indirectly the members of the Vegetable Eingdom help largely to 

 thin the ranks of the little creatures which visit them. 



To ''begin at the beginning," we must go back to the old pre- 

 historic times, when insects had nothing to fear from man's organ 

 of inquisitiveness ; for the simple reason, that man did not then exist ; 

 or, if he did walk the earth, his intellect was of the lowest, and 

 collections and museums were undreamt of. I allude to the days 

 when amber was forming, and vagrant insects were every day being 

 entangled in its viscid toils, and there preserved for the wonder and 

 admiration of modem scientists. Amber is a semi-transparent sub- 

 stance of a light yellow or brown colour, capable of taking a high 

 pohsh, and therefore is much employed in the manufacture of heads 

 of canes, mouthpieces of pipes, necklace beads and such small 

 matters. Probably the most important use that has hitherto been 

 made of amber is to be seen at Zarskoja-selo, a favourite residence 

 of the Czars of Russia, not far from St. Petersburgh. Here there 

 is a room, about thirty feet square, the walls of which from floor to 

 ceiling are entirely lined with this substance.* It was presented 

 by Frederick the Great to the Empress Catherine, whose initial E 

 (Ekatarina) is interwoven with the Prussian arms in the devices on 

 the walls. If we may give credit to old Homer, this is not the 

 first time that amber has been used for the decoration of a palace ; 

 for he writes, 



" The spoils of elephants the roofs inlay, 

 And studded amber darts a golden ray."t 



The principal source of supply is the coast of the Baltic Sea in 

 Eastern Prussia, between Memel and Dantzic, where it is dissem- 

 inated in the sand or clay. It is searched for in the sea or on the 

 shore, or is picked from the cliffs with iron hooks at the end of 

 long poles, or lastly it is regularly mined, the shafts sometimes being 

 sunk to a depth of a hundred and fifty feet. Saxony supplies a 

 small quantity, in bituminous clay mingled with lignite. It also 

 occurs in Sicily in beds of clay and marl ; in Poland it is found in 

 sandy districts at long distances from the sea ; it also occurs in 



*A. B. Keichenbach (VoUstandige Naturgeschichte). 

 tHomer (Odyssey, iv. Pope's Translation). 



