160 TURNIP, 



principles have been expected to be distributed over the country where 

 its food-plants are mostly distributed. But if by auy strange and 

 unaccountable chance it had only been bred along the coast, it is 

 almost impossible that the ravages of the myriads of caterpillars which 

 must have forestalled the moths to which they presently developed 

 should have escaped observation, It will also be seen by collating the 

 " replies to inquiries " (Nos. 5 and 6), that for the most part there had 

 been no particular weed observed, nor special presence of Charlock, 

 nor difficulties in proper cultivation of the land. 



The crop food-plants, whether field or garden, are of kinds to be 

 found in all cultivated districts ; and of the weed food-plants, as Char- 

 lock, Jack-by-the-hedge, Flix-weed, and others named on (jond authority 

 as frequented by the pest, I only find two which occur (respectively), 

 one ordinarily, one exceptionally, on the sea-shore. 



Of these, one, the DipJota.vis temiifulia (the narrow-leaved Wall 

 Mustard or Wall Rocket), occurs in England by roadsides or on old 

 walls ; in Scotland it is recorded as not being found further north 

 than Fifeshire, and occurring on the ballast hills at St. David's on the 

 Firth of Forth. The other, the Sahola kali, or Saltwort, is found on 

 sea-shores.* 



In any case, however, as to this, it appears to me that such a very 

 small proportion of the food-plants of which we have notes on any sort 

 of authority are sea-side plants, that we have no reason here which 

 explains a prevalence upon this one sole occasion on record of an 

 extraordinary amount of outburst along our eastern coast. 



At first the caterpillar ravage threatened to sweep all before it, and 

 was variously reported as having entirely " destroyed " crops under 

 observation ; as " making havoc," " devastating the fields " ; " brutes 

 eating all in front of them " ; " likely to be most disastrous to agricul- 

 turists " ; causing destruction to hundreds of acres, &c., and naturally 

 wide-spread uneasiness arose. This was enhanced by the destruction 

 being so rapid. In this case, as with many other kinds of crop attack, 

 the damage being little observable until " the brutes " have their eating 

 powers well developed, the rapidity of the after progress is all the more 

 remarkable ; the myriads of nearly full grown eaters make way 

 quickly. 



The rapidity of the devastation was noticed by Mr. Garrett Taylor 



* This is given by Dr. E. L. Taschenberg (in his ' Praktische Insekten-Kunde ') 

 as a food-plant of the Diamond-back caterpillar, and on his excellent authority I 

 have repeated the statement in some of my publications ; but I have not received 

 any reports of caterpillar presence on this plant, and am informed by Mr. Atmore, 

 of King's Lynn, that in his investigations on the shore where both Saltwort and 

 Diamond-back Moths weie present, that he has not seen that the caterpillar was 

 present on the plant. — Ed. 



