10 



mycorhyza to which I have already referred. Abnormalities! 

 constantly occur in a wild state, and still more in our gardens, 

 which may throw important light upon structure, and often in 

 this way suggest modifications in our classifications. Besides 

 those familiar physiological topics that were illuminated by the 

 work of the last years of Charles Darwin, climbing, carnivorous- 

 ness^ and the wide field of pollination, with the subsidiary subject 

 of hybridism, there is the most important series of questions as 

 to how far certain cases of apparently parallel development 

 among plants living under similar conditions are indicative of 

 real affinity, or community of descent, or how far they are merely 

 adaptational, how far they may be directly produced by the 

 stimuli of external conditions, or how far, if so acquired, their 

 characters can be hereditarily transmitted. To this question, 

 which lies at the very root of the controversy between Weismann 

 and the Neo-Lamarckians, it seems rather as if at present 

 botanists were disposed to give an opposite reply to that of 

 most zoologists. 



There are many groups of animals, such as earth worms and 

 spiders, and I may, perhaps, add marine worms, leeches and crabs, 

 which have only one or two men in the whole kingdom devoted 

 to their study, and which yet are handy enough for any of us to 

 study, and would throw as much light upon the fundamental 

 problems of biology as any of the more popular groups. Our 

 land and fresh water mollusca present interesting questions as to 

 distribution with reference to soil and the hardness of the water. 



Passing on to the Arfchropoda, Huxley's Grayfiih, Miall's 

 Cockroach and Lowne's Blowfly, together with such works as 

 those of Lubbock and Packard seem to specially invite us to a 

 detailed study of comparative anatomy and developement, whilst 

 the complex symbiotic conditions of bees, ants, ichneumons and 

 gall flies equally attract us in the direction of pure observational 

 study of the life histories of living insects. There is plenty to 

 be done in the intelligent collecting and study of the micro- 

 lepidoptera, and, even among the too commonly collected macro- 

 lepidoptera, such ubiquitously abundant species of the cabbage- 

 whites and the common blue present most interesting series of 

 variations in size and marking, which seem, at least in the latter 

 case, to be connected with geographical range. Other groups, 

 such as the Diptera, Hymenoptera and Coleoptera, have as yet few 

 workers devoted to them in any district ; and, whether in the 

 discovery of new species, the working out the distribution of 

 those already known, the tracing of food-plants, or other points 

 jn the life history, offer abundant promise of valuable results. 



