364 RECREATIONS OF A NATURALIST 



over and over again until the fluid becomes filled 

 with these little bubbles, and assumes the appear- 

 ance of froth." 



The larvae are plentiful in spring, while the per- 

 fect insects abound most in autumn. 



According to Professor Westwood a species of 

 Aphrophora is found abundantly on trees in 

 Madagascar, the larva of which has the power of 

 emitting a considerable quantity of clear water, 

 especially in the middle of the day, when the heat 

 is greatest. A still more curious case is that of the 

 tube-making homopteron, allied to Aphrophora 

 already referred to, as found in Ceylon. The full- 

 sized larva tubes are about half an inch long and 

 about one line in diameter, of the thickness of 

 writing paper, of a dirty white colour, with the 

 surface finely transversely wrinkled, the basal 

 portion being dilated and curved so as partially to 

 clasp the twig on which it is fixed. The larva 

 resides in the tube, and discharges at intervals a 

 clear watery fluid, which escapes from the tube drop 

 by drop. 



The phenomena known as " weeping trees " are 

 due to insects of this family, the Cercopidce ; some 

 of the species, says Dr Sharp, make such copious 

 exudations of this kind that the drops have been 

 compared to a shower of rain (Cambridge Natural 

 History, "Insects," p. 577). 



As an illustration of the inconvenience which 

 arises from changing well-known names, it may 

 here be remarked that Dr Sharp calls the English 

 insect Philcenus spumarius, but although he devotes 



