524 GENERAL BIOLOGY 



grafting (budding) is available for late summer, where 

 mature buds are selected for immediate transplantation. 



Cone galls, needed for study 42, abound on the tips of the 

 twigs of our common glaucous willows, along streams and in 

 sunny wet places generally. The gall midge larvae spend 

 the winter in the galls, fully grown, and transform in early 

 spring. If brought into the laboratory any time after 

 Christmas (or after heavy freezing has occurred) they will 

 enter the pupal stage in a few weeks or less, and adults will 

 appear two weeks thereafter. Individual lots collected by 

 students may by them be tied up in squares of cheese-cloth, 

 and the midges will develop normally if the galls be wetted 

 about once a week, (as by holding them under the water tap, 

 or by immersing them for a minute in a bowl of clean water). 

 Data given in chapter I, (pages 44 and 45), will suffice for 

 distinguishing the midge larvae from their parasites (which are 

 sure to be numerous) and from the other occupants of the 

 galls. (See figure 36 on page 46.) 



A biological garden, while not absolutely required, is the 

 best possible equipment for the sort of a course this book 

 proposes. It need be a little more than a pond or a brook, 

 and a few little border plantings. There should be enough 

 of it for supplying stores of fresh materials for class use, 

 and enough for connecting the work of the student upon 

 living things with the world of which they are a part. 



If time can be taken for but one of the introductory 

 studies on the relations between flowers and insects, Study 

 5 is the one that should be chosen. Full blooming clumps 

 of flowers (preferably of some specialized bumble-bee 

 flower, such as the snap-dragon, the great blue lobelia, 

 butter and eggs, or turtle-heads) will be needed. If not 

 accessible in nature, they may be easily provided with a little 

 forethought at planting time: all give handsome landscape 

 effects in border plantings. 



