222 The Aims of Field- Club Excursions. [Sess. 



(6) Visit to pond or swamp. Fresh- water insects, — try to 

 get some gnat larvfe in summer. Fresh-water algse, conjuga- 

 tion in various forms. 



(V) Shore walk for marine algce. At Musselburgh, the 

 parasitic worm in cockles might be found : consider formation 

 of pearls. 



(8) A tow-netting excursion, by which means enormous 

 numbers of organisms and larvee of many kinds may be ob- 

 tained : Plankton. 



(9) An excursion to illustrate biology of microscopic 

 fungi, summer and winter quarters on different hosts, &c. 

 Look for mycetozoa : try to grow some at home. 



(10) Uxcursion to look for galls — changes of tissue due to 

 irritation. Notice also witches'-brooms. Galls may be taken 

 home and gall flies caught when they emerge. 



(11) Many biological facts should have excursions devoted 

 to their illustration — e.g., parthenogenesis, aphides, ants and 

 their cows, social and solitary insects. Daphnias and their 

 eggs (winter female ; summer unfertilised). 



(12) Having most fortunately this winter learned much 

 of the structure of insects, an excursion or two might be de- 

 voted to insects. 



(13) An afternoon might be well spent in studying weeds. 

 I don't mean by weeds simply wild plants, but wild plants 

 which appear in our cultivated fields and gardens, occupy the 

 soil we till and prepare for crops and flowers, and enter 

 into the struggle for existence with these for food and sun- 

 shine. Heath and rock-roses are not weeds. Where do the 

 weeds come from ? Seeds wind - carried, like dandelions ; 

 seeds ripened earlier than the crops (poppies and wild must- 

 ard) ; brought by human agency (finger-and-toe disease with 

 manure) ; introduced with cereals. 



We have, in studying a garden or a farm, a fine thought- 

 model for human society. Human society, unlike animal 

 communities, can plan its own development — a thing which 

 it rarely does in any efficient way. Garden cities are a 

 spendid idea, — only, to be really successful, human society 

 must adopt some means of keeping down human weeds within 

 them, and it should have clear ideas about what weeds are. 



(14) If we could see cheese-making on scientific principles 



