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THE YOUNG NATURALIST, 



the exception of the specimens being very small, and the central spots tending 

 to become confluent, they were simply small lonicerce. In 1881, when I 

 next visited the ground, they were still abundant, and were now real, un- 

 doubted trifolii, smaller than in 1877, many with their spots completely 

 coalesced, and among them one variety, luiescens, with yellow spots. The 

 pupae were characteristic trifolii, and did not, as in the case of lonicem, spin 

 their cocoons on the stalks of their food-plant grass, &c. I could not find, 

 moreover, a single point of difference between the larvae of the form in the 

 field and those of lonicerce in the wood. But the most remarkable thing was, 

 that in 1881 they appeared earlier, and in 1882 they appeared on June 14th, 

 but in greatly diminished numbers. In 1883 they again appeared in the 

 middle of June, but there were very few, and since then they have been 

 absent altogether. I remember once an old collector saying to me : " You 

 can get both the five spots down there, but one of them only occurs some- 

 times, after the wood is cut down. They will occur for a few years and then 

 you must wait." I believe this statement contains the whole secret of the 

 matter. When the narrow belt of brushwood is cut down, I am of opinion 

 that lonicerce spreads into the field, and instead of feeding on the tall succulent 

 vetches which are so abundant in the wood, it has to content itself with the 

 low-growing vetches in the field where the tall Vicias do not occur. The first 

 element, therefore, in this probable development is phytophagic, then the more 

 exposed nature of the field as compared with the wood, and the drier nature 

 of the soil, naturally does its share of the work, and a form is produced very 

 different to lonicerce type. Why it should become extinct, I am, of course, 

 unable to say. Certain it is that a process of deterioration gradually goes on 

 owing probably to phytophagic or altered conditions of environment, until 

 the miserable little specimens which are produced die out. I believe there 

 is no genus which is more directly influenced by its surroundings than this. 

 The lonicerce, which occur in the wood I have before referred to, are always 

 smaller the two years succeeding the cutting down of the wood, but soon 

 attain their normal size. I do not, however, think it wise in the present in- 

 definite state of our knowledge, that the above supposition should be taken 

 for granted. I assume that specimens of lonicerce do pass from the wood to 

 the field, and that then certain changes go on. I cannot prove this, and I 

 trust no one will yet suggest, unless something much more definite is known 

 by other lepidopterists, that any change in the treatment of trifolii and 

 lonicercs as distinct species should take place. The idea of treating trifolii 

 as a variety of lonicerce on the above evidence would be absurd, whilst the 

 breeding of trifolii from ova of meliloti, or var. ytennsis, Briggs, is most con- 

 clusive. 



