408 ENEMIES OF APHIDES. 



Fiofs. 3 and 4. — Veins showing the ringed tracheae within. The dia- 

 meter of the tracheal tube is about 2 2V2 ^"' 5 ^"^^^ ^^ ^'^^ ^^^'^ 

 is about 4^g in. 



,, 5. — Wing of the male of a smaller species of Chrysopa, drawn 

 directly from the insect. 



,, G. — Wing of Hemerobius, drawn under the same conditions as the 

 last figure, illustrating the differences in structure and 

 venation. 



, , 7 — Antenna of Chrysopa perla. consisting of a very large number 

 . of similar cylindrical joints. 



8. — Antenna of Hemerobius, exhibitingr the moniliform structure. 



Cbange of Hir. 



THE necessity for change of air not only during convalescence 

 from illness, but as a means of maintaining the normal 

 standard of health, is now generally recognised. The father 

 of a family who fails to make some arrangements for giving his 

 children an annual holiday, either at the seaside or elsewhere, is not 

 acting judiciously. Young people who live in large towns and who 

 have comparatively little opportunity of indulging in outdoor games, 

 and getting healthful exercise, soon " run down " and become 

 depressed and debilitated. Many people seem to think that a pre- 

 liminary illness is requisite as a justification for a holiday, but there 

 can be no doubt that there would be very much less illness if 

 change of scene and air were regarded as necessities of life. One 

 annual outing is not enough for the maintenance of robust health, 

 but should be supplemented by excursions five or six times a-year. 

 People are waking up to the absolute necessity of varying their 

 ordinary daily toil with periods of relaxation. English people are 

 energetic enough in what concerns business matters, but as a rule 

 take their pleasures sadly, which may possibly arise from the feeling 

 that they are doing something unusual. The breadwinner of a 

 family who cannot take a holiday in the summer should set aside a 

 weekly sum as a nucleus of a " pleasure hoard " to be devoted to 

 recreation. A man with an assured income of ^300 is justified in 

 spending 5s. weekly for this object, which would give a family each 

 week's end invigorating exercise in the fresh air. When a holiday 

 is taken the programme should be minutely worked out before, or 

 there will be loss of valuable time. Trips arranged systematically 

 every week not only afford a vast amount of pleasure, but obviate 

 resorting to the doctor and the chemist. — " T/te Faftiily Physician'' 



