12 



CIVIC BIOLOGY 



continue the study after the course is completed, it would be 

 well if each could be given the chance to make at least the 

 two collecting nets and a small aquarium for himself. 



Materials for making the nets. Flat-drawn spring brass or tinned steel 

 wire for the frames for the air and water nets respectively ; the strong- 

 est cotton tape (mill tape, such as is used in wrapping electric wires, 



FIG. 5. Easy construction of insect net 

 1, form of wire frame ; 2, slipping net on frame ; 3, net bound to handle with twine 



is good) ; then for the air nets, strong bobinet, light cheesecloth, or 

 mosquito netting, according to preference. Mosquito netting, if the 

 threads which cross run the long way of the net and care is observed 

 to avoid water and briars, makes a fairly serviceable insect net. For 

 the water nets use cotton scrim. There are several ways of making the 

 nets, but for nets detachable from the handles the writer has found the 

 method shown in Fig. 5 most serviceable. 



Materials for aquaria. The aquaria may be made for little more than 

 cost of glass, the materials being : 



