123 



placed on some trees in different places, and in every case only 

 females were produced. These were transferred to other places, and, 

 time after time, there were nothing but females. This had been going 

 on since 1869, and no males had been discovered. 



Mr. J. E. Haselwood said it had been noticed that the aphides 

 during the summer produced only females for ten generations, but 

 when the weather was colder and there was less nutrition, both sexes 

 were produced. To test this, some had been kept in warm atmo- 

 sphere and supplied with plenty of nutrition, the result being that 

 during four winters only females were produced, thus proving that the 

 cause of sexlessness was the abundance of nutrition and temperature. 



Mr. GOSS said such an instance was quoted by Von Siebold. 



Mr. Haselwood did not see why all the necessary conditions 

 should not be completed in one as well as two. It was said that the 

 ovaries began to develop before impregnation, and when they reached 

 a certain stage, if not impregnated, they decayed. 



Mr. WoNFOK said there was another point with regard to the 

 aphides. There was a miscroscope slide commonly marked "leaf 

 insect," in consequence of it being covered with leaf-like appendages. 

 That was merely one form of the maple leaf insect, and which also 

 would be found on the sycamore. These peculiar females produced 

 two species, one capable of producing their kind exactly alike, and 

 the other incapable of producing its kind. 



It was remarked that Darwin had pointed out that uni-sexual 

 germination was the rule when the organism was not so de\'eIoped ; 

 but when it became more complex bi-sexual re-production became 

 the rule, the latter having a greater tendency to sustain the form and 

 to give a longer duration of life than the other. 



"A NEW SPINNING JENNY." 



Mr. F. C. Dennet brought before the notice of the meeting a 

 new machine for spinning cotton that had been invented in America, 

 prefacing it with a statement of the futility of the attempts made in this 



