i86 LETTERS TO DR. HOWARD [CHAP. xvm. 



seven contiguous counties in the South-west of Scotland, 

 and though not remarkable in itself, yet, as there were one 

 or two competent observers on the spot, some good notes 

 were secured, especially as to presence of parasites, which I 

 hope in due time you may find of some interest. There was 

 much presence of a Mermis in one district. Out of a single 

 larva I withdrew in three pieces about 18 inches of thread- 

 worm. Also there was presence of " flacherie " and some 

 Tachina larvae. Dr. Ritzema Bos, of Wageningen, who is 

 always most kind in colleagueship, helps me much about 

 identification. 



I hope to have a good deal to say about Heterodera 

 schachtii (an eel-worm enemy of hop-roots). Different 

 kinds of eel-worms seem each year to be showing them- 

 selves more, and I am greatly desiring to find whether the 

 schachtii may not have come to the roots of oats here as 

 well as in Holland. The Great Tortoiseshell butterfly, 

 Vanessa polychloros (fig. 13), which is not common in this 

 country, made a destructive appearance on elms and cherry 

 leafage in one locality in Hants. And not far from 

 Lymington was a destructive attack in one wheatfield of 

 the caterpillars of a small moth, which ate out the heart 

 of the young plant and was utterly ruinous. I cannot find 

 the kind of attack on record (that is from a Lepidopterous 

 butterfly or moth, larva), and we are all perplexed as to 

 species. There seems little doubt that it is a Miana, and it 

 appears to me most like expolita, but none of us contrived 

 to rear it. 



March 23, 1895. 



I have been long in your debt for a letter, but sometimes 

 it is very difficult to keep all work in hand, and I am sure 

 you will forgive me. I had been endeavouring before your 

 letter on Warble came to hand, and have since also been 

 trying in some of what appeared the most likely quarters to 

 gain information whether the form of attack which you 

 mention in the U.S.A. was observable here, but as yet I 

 have not been able to find that such is the case. 



Many thanks to you for your presentation copy of your 

 most interesting paper on " Rise and Progress of Economic 

 Entomology," and your only too flattering mention of my 

 own work (pp. 295-97). O n * ne continent of Europe there 

 is grand work going forward, and the colleagueship I 

 am favoured with from many of the leading Continental 

 Government Entomologists is most kind and gratifying 

 to me. 



