EVOLUTION OF OUR KNOWLEDGE OF THE BRITISH RHYNCHOTA. 61 



coloured plates), and in the last year of the century Newstead is 

 reported to have completed an account of the Coccidae'''- , and Scott had 

 already long ago revised the Psylliilae, so that now, at the threshold of 

 the new century, we have a practically complete systematic account of 

 the whole order. For the student of British forms, the work of the 

 future undoubtedly lies in their anatomy and life-histories. Outside 

 the Coccidae, Aplwlae and Psijlliilae (with the literature of which I 

 regret I have not yet found leisure to make myself familiar), there is 

 not, I believe, a single species of Rhynchota of whose life-history and 

 metamorphoses we possess a knowledge in any way comparable with those 

 we have of hundreds of lepidoptera, coleoptera, hymenoptera, odonata, 

 and even of diptera. Mr. Enock, most careful of observers, is studying 

 the biology of water bugs, but there is still an enormous field open for 

 research. 



To demonstrate the interesting character of some of the known 

 habits of bugs, I will mention tAvo of the more remarkable, viz., the 

 parental care of the Cimicid, Elasmiicha inte rati net K!<, shown by the 

 female for her young, originally pointed out by de Geer and sub- 

 sequently verified by Hellins (see, Saunders' Hemiptera Heteroptera, pp. 

 37-38), and the details of the copulation of (xerrk canalinm 

 as narrated by Meinert and verified by Kirkaldy (see, Entuwoloijist, 

 1899, pp. 201-2). As to anatomy, the most significant statement that 

 can be made is that the standard work on the general subject is 

 Dufour's lu'cJierches siir les Hemiptevey. (1833, ^Icm. Acad. Iloij. Sei. 

 France, Savans. Etrang., pp. 129-462, 19 plates), published nearly 

 70 years ago. In 1899, Heymons of Berlin produced a most important 

 work on the anatomy of Rhynchota (" Beitriige zur Morphol. und 

 Entwickl. der Rhynchoten," in Nura Acta, Lcop.-CarttL Acad., 

 Ixxiv., pp. 349-446, 3 plates), which, however, is chiefly morphologico- 

 embryological, and scarcely covers Dufour's ground. 



In conclusion, if there be an enthusiastic young entomologist 

 anywhere in the British Isles, who has plenty of time upon his hands, 

 and is desirous of studying the Rhynchota, I venture to suggest that 

 he collect and study one of the following genera, viz : Gerris or 

 Bednviolm (Xabis, Saunders). In (rerris there are ten species, of 

 which seven may be reasonably expected to reward his efforts in a fair 

 district. Of these ten, four are nearly always macropterous, five are 

 found fairly commonly in various condition of wing-development, and 

 one is nearly ahvays apterous. In nediiriolus there are ten or eleven 

 species, of which eight or nine should be among the first or second 

 season's spoils ; of these, five species are nearly always apterous or 

 very brachypterous, in four the condition of the wing development is 

 somewhat varied, while one species is almost always macropterous, 

 lU'dnvioliis being thus a complete reverse of Gerris. The collection in 

 considerable numbers and from diverse localities of the species of tliese 

 genera, their comparative tabulation, the percentage of the various 

 forms, Szc, and moreover their rearing up ex oro, with experiments to 

 determine if possible what stimuli produce this " pterygopoly- 

 morphism," in other words, this occurrence of different forms of 

 structure and development in the flight-organs of the same species, 



* I have not yet seen the work, so I'egret that I can say nothing aLout this 

 most interesting family. — G. W. K. [See antea, p, 59. — Ed.] 



