( XXX ) 



this bottle are still alive, or at least supplied with sap. In the two former 

 cases the roots had become mouldy, but in this case there is at present no 

 appearance of fungus growth. 



We see, then, that in the two bottles where the roots completely died 

 and commenced to decompose as many as over sixty winged forms have 

 appeared, whereas in the bottle in which the roots have kept alive not a 

 single winged form has appeared. 



I should add that bottles A and C were supplied with vine-roots from 

 the same vineyard ; but those in bottle B were taken from another vineyard 

 some five-and-twenty miles distant. 



The wiuf^ed individuals that I have thus bred in confinement, have 

 never lived more than three or four days. They have laid eggs whilst 

 confined in a glass cell. In one instance two eggs were laid, and, 

 on examining the insect under the microscope, a third was seen in the 

 abdomen. I have also a specimen showing three eggs in the abdomen, 

 another with two, and another with one ; also another with what appears 

 to be oranular protoplasm in the abdomen. The maximum number of eggs 

 laid appear therefore, from experiment, to be three, which I think is the 

 number mentioned by M. Cornu. 



1 believe it is considered doubtful whether the produce of the winged 

 form should be distinguished as an egg proper, or whether the alate form 

 should not be considered viviparous, the apparent ovate body being perhaps 

 nothino more than a pupa or chrysalis enclosed in a membranous investment. 



But, if it is admitted that the apterous parthenogenetic larva is an egg- 

 layer, then I think it should be conceded that the alate form is equally 

 oviparous, because, after their exit from the body of the parent individual, 

 it would be very difi&cult for an ordinary observer to distinguish one from 

 the other ; both are of an oval shape, of a bright yellow colour, easily to 

 be seen by their glistening appearance, and of a sticky exterior. 



Perhaps the remarks of Balbiani, as quoted by Mr. Buckton ('British 

 Aphides,' iv. 73), will afford the best reason for describing these ovate 

 bodies as eggs, for they entirely conform to his definition, viz. : — " Si Ton 

 doit appeler des ceufs de corps qui sont constitues essentieUement comme 

 les oeufs des autres insectes, qui se segmentent et dans lesquelles, les 

 parties d'embryon se forment successivement et peu a pen : ces corps sont 

 des (eufs vi non des piipes comme jel'ai toujours soutenu." 



Whilst in the body of the parent individuals the eggs appear to be 

 enclosed in a sort of envelope, but this does not appear to surround each 

 e"'T, but encloses the whole of them, one, two, or three, as the case may be. 

 The microscopic slides which accompany these remarks will show this. 



When the eggs, however, are extruded, they no longer seem to possess 

 this envelope, and, in fact, as they are only laid one at a time, it would be 

 impossibk'. Therefore, I suppose the fact ol their enclosure in the envelope 



