180 ■ •[Jinuary, 



vfith pseudofjj/ncB aw^ i^ibpiferce, bringing their male and female pupse, 

 whicli burst open in a very sliort time, giving issue to the "perfect" 

 form, which is very imperfect indeed in these creatures, as they show 

 only the organs of generation and nothing else. 



Now the last step must be narrated, the last proof must be 

 afforded. Out of the eggs concealed in the dried skin of the mother 

 I must obtain th.e pseudogyna fundatrix, and see her form her gall on 

 the young elm-leaf. This proceeding has already been so well observed 

 and described by Prof. Kessler, that, besides the fact of seeing the 

 fundatrix of the gall coming out of the egg proceeding from the grass- 

 root lice, I will have only to follow and confirm his observations. 



At the same time that I discovered Tetr. uhni on Cynodon roots, I 

 could also establish more surely the kind of grass on Avhich the second 

 species of Tetraneura of the ehn feeds, which I named Tetraneura 

 rubra, because the gall is red. 



I had written to Mr. Buckton and others that it was Triticum 

 caninum, but this spring I had the species of grass more certainly detei*- 

 mined by Prof. Planchon : it was Fanicum sanguinale. The young 

 lice of Tetr. ruhra are reddish, while those of Tetr. uhni are white, and 

 in the winged pupiferce the 5th auteunal joint is shorter than the 3rd, 

 while they are equal in Tetr. uhni. 



So I can affirm that Tetr. uhni passes the summer as an under- 

 ground plant-louse on grass-roots (maize or Cynodon*),M\A Tetr. rubra 

 on Panicum sanguinale. 



The three other gall-lice of the elm, viz.. Pemphigus paUidus, 

 Haliday, Schizoneura lanuginosa, Hartig, and Schizoneura uhni, Kalt., 

 also assume their winged pupiferous form on the elm-trunks, but I 

 cannot yet discover where they come from. I fancy that Buckton's 

 Schiz. fodiens, feeding on black-currant roots, might be the under- 

 ground form of Schiz. uhni ; at any rate, the antennae are entirely 

 similar, according to Buckton's figures, but, of course, this is only a sup- 

 position, and more evident proof requires to be given. 



Montpcllier : Srd December, 1883. 



* In quoting two species of gra.sses on which I found the under -ground form of T. uhni, I do 

 not wish to assert that it may not occur on other grasses. On the contrary, for Passerini has 

 found it also on several species of Sorghum, Panicum crue-yaUi, Oryza montana, Uraproftis ?n«- 

 pastachys. Lolium perenne, Cuix lachryiaa, &c., so it is very likely that, in England, the insect 

 resorts to species of grasses more common there than are maize or Cynodon. Jlr. Buckton sa3's 

 he has found the species plentifully at the roots of Hieracium murorum, H. sabaudiim, and Lactuca, 

 b\it I think there is some error, for the antennie (Brit. Aph. , ii, pi. ex, fig. 31, do not at all resemble 

 those of Low's P. zecB-mohlix, in which the 5th joint is equal to the 3rd, and I think Mr. Buckton's 

 insect will some day prove to be the under ground form of some poplar galllousc, perhaps 

 P. bursarius or pyri/ormis, but, of course, proof is neces.sary to sustam my hypothesis. Ttlra- 

 ntwa rubra has not yet been found in England, and this is, perhaps, owing to the scarcity there 

 of Panicum scuiguiuatc—J. L. 



