NO\EMBER, 1910. 



KNOWLEDGE. 



beautiful aud extraordinary ciliated appendages, xvith which 

 It continually sweeps" the water in search of food 



Professor Miall. in his admirable Natural History of 

 Aquatic Insects, deals verv fnllv with this larva but 



4.i3 



4th. and when I left on August l-'th, practically all had pupated. 

 The Hies were due to appear d.irins the last week in August 

 and these I unfortunately missed. 



The Fly in this country is harmless, but others of the genus 



FiGfRE 1. 



The larva of Siiiiuliuiu rcptaus. 



curiously enough, only refers to the most prominent, or 

 external, pair ot sweepers. A smaller pair, within the larger 

 IS however, easily visible with a low power of the microscope. 

 These appendages the larva keeps constantly in motion, and 

 all food withm their range is instantlv swept into the capacious 

 mouth. 



The larva pupates within a conical silken cocoon, which it 

 hrmly attaches to the weed with a glutinous secretion of both 

 silk and cement supplied by the saUvary glands. The cocoon 

 is very transparent, and enables one to readily make out 

 details of the imago within. The pupa is prox-ided with 

 dehcate tubular gills, visible in the photograph, for breathin- 

 purposes. " 



Unfortunately, my stay in the countrv was too short to 

 make complete observations; when I first examined the weed 

 (July 24th) I found larvae only, a few pupae were found August 



Fic.ruE 2. 

 The pupa of Siiuuliuni rcptans. 



^f^^l^^>/^ 



Figure 3. 

 The head of the lar\ a showing mouth aud thoracic claw. 



m the United States (8. molcstuiii) and the \alley of the 

 Danube (S. columhaczcnsc) form a terrible scourge, in bad 

 years driving cattle mad by the hundred. The insides of the 

 ears and nostrils are the favourite points of attack— to such an 

 extent indeed, that these organs are packed almost solid in 

 bad cases. Fortunately, the family is a small one, containing 

 but one genus and about sixty known species. 



The larvae I failed to keep in aquaria, as might be 

 expected from their normal habitat, all dying in a few' hours. 

 They might possibly be reared in aquaria violentlv aerated by 

 mechanical means. In a round tank a steadv, well-aerated 

 flow of water could easily be assured, that would give a good 

 imitation of their natural surroundings. 



The final metamorphosis of the Fly is most interesting, 

 but this I missed, as above mentioned. The perfect insect 

 leaves the cocoon in a bubble of air, floating in safety 



