156 



HARDWICKE'S SCIENCE-GOSSIP. 



the cerebral nerves are those mostly concerned in 

 these eye movements. 



I recommend the boycotting of all picture galleries 

 and other exhibilions where catalogues are sold. 

 Such catalogues are paltry devices for the extortion 

 of an additional fee, and obtaining payment for 

 advertisements therein. Any picture or other object 

 that is worth exhibiting is worth a descriptive label. 



Sparrows. — Among the readers of Science 

 Gossip are many observers of the habits of animals ; 

 I therefore note the following as suggestive of further 

 observation and experiment. I reside in an old 

 house with old-fashioned sunblinds outside, and old 

 creeping plants on the walls. In the course of 

 exterior painting, the workmen pulled down a 

 barrow-load of sparrows' nests from the sunblinds 

 and honeysuckle. In the course of a day or two they 

 were all rebuilt in their old places. This was 

 repeated four times at varying intervals, some of them 

 long enough to allow for a fresh supply of eggs, and 

 even the hatching of young birds. At the present 

 time (June 22nd) the fifth series of nests are in their 

 old places. Query : What is the limit of constancy 

 and perseverance of these birds ? 



I see that the newspapers are reviving the old story 

 (superstition I call it) of sparrows saving fruit trees 

 by eating caterpillars ; sparrows have been killed in 

 Kent, and certain fruit-trees have been attacked by 

 caterpillars — ergo, sparrows feed on caterpillars. It 

 would be well if the inventors of these stories would 

 examine the crops of a few sparrows, and learn 

 thereby whether caterpillars or fruit buds and seeds 

 are the most numerous therein. I may add that in 

 my own garden, which is infested with sparrow 

 vermin, a plague of caterpillars also prevails, and the 

 fruit trees are suffering as in Kent. 



NOTES ON THE DEVELOPMENT OF THE 

 GNAT {TIPULA PLUMOSA), LINN. 



By Harry Thomas. 



Description of the Larva. 



[Continued from p. 133.] 



THE head of the larva is comparatively large, the 

 body tapers gradually, and is divided into 

 twelve segments. The head is provided with four 



filiform processes. Upon either side beneath the 

 clypeus is a well-developed toothed mandible, and 

 below a comb-toothed labium with a broad basal- 

 jointed maxilla upon each side of it. Immediately 

 beneath the clypeus, upon each side, apparently 

 attached to its lower surface, are two chitinous 

 toothed ridges, and lying between them a triangular 

 toothed ridge surrounds the oral aperture. 



The segment next the head, carries ventrally a 



i ■ ■ 



/ 



A ^ 



\o 



V 



Fig. 61. — [a) digestive system; (3) lower 

 view of the head. 



L- 



// 



Fig. 62. 



Fig. 60. — Diagrammatic figure of young larva. 



compound eyes, two antenna, and the following 

 mouth parts : — the clypeus appears jointed between 

 the antennce : it carries on its outer margin a delicate 

 transparent labrum, bearing on its free edge six short 



process from which two rounded prominences covered 

 thickly with fine hooks, arranged in parallel lines, 

 serve as anterior limbs. These hooked processes can 

 be retracted into their common cushion by muscles 

 attached to their anterior walls. 

 The following ten segments carry 

 no appendages, but the 12th 

 carries the two posterior limbs, 

 very differently formed to the an- 

 terior. They are cylindrical and 

 tapering, and carry at their ex- 

 tremities some twelve strong hooks, 

 also retractile, although the limbs 

 themselves are but slightly so. Posteriorly this seg- 

 ment carries four oval processes, and dorsally two 

 small globular bodies, each supporting a few stift 

 bristles. 



