£G THIRD ANNUAL REPORT OF 



and no doubl their habitat is governed somewhat by the character of the soil, though in this country 

 their normal habit is to attack the roots, ami to appear above ground only occasionly in the fall. 

 Secondly, we have proved, by transferrins;- on to roots the young: grape-lice hatched from galls, 

 ami by successfully feeding them on those roots, thai our smooth gall-inhabiting type gives birth 

 to Ihc tubercled root- inhabiting type; ami we have discovered thai our -all insects take to the roots 

 in the fall, on which they cause the same cankerous spots and swellings as does the vastalrix of 

 Europe, and on which they evidently hibernate just as vastatritviB known to do. 



Thirdly, although in the gall-inhabiting type, in both countries, the tarsus seems to beone- 

 jointed, yet in Hie root inhabiting type it is reallj two-jointed ; for though the basal joint is small, 

 and not \ isihle from above, it is plainly visible from the side or from below (See Fig. 40, b). We 

 have here what certain speculative entomologists would consider an excellent illustration of the 

 inferiority of Coccidse compared with the Aphidss, namely, a true Aphidian, exhibiting in its larval 

 and agamic stage the one-jointed tarsus of a Coccid, and only showing the two-jointed tarsus of its 

 family in the more perfected tubercled form, and in the winged state. And this Coccid-affinity in 

 the less perfect gall-producing state is sometimes carried still farther, as we have often been unable 

 to discern but a single claw to the tarsi of some of the young gall-inhabiting individuals. 



Fourthly, the fact that M. Signoret, who alone has compared actual specimens from both 

 countries, decides them to be identical, would sufficiently indicate that the difference noticeable in 

 the form depends on the observer, and on the stage of growth at which observations are made. 



It was the one-jointed tarsus in the gall insect which no doubt in part led Dr. Shimer to pro- 

 pose a new family for it, and it was this character — coupled with the facts that it is oviparous, that 

 does not secrete any sugary or flocculent substance (as do most gall-inhabiting Plant-lice), and 

 that the young forsake the gall and scatter over the leaves as soon as hatched— which led Mr. 

 Walsh to consider it as an anomalous and aberrant Coccid. The genus Phylloxera seems also, ac- 

 cording to Westwood, to have been doubtingly introduced into this family by Curtis in his Guide. 

 We have already shown that, in the root-inhabiting form, the two joints of the tarsus are plainly 

 to be seen ; and Dr. Shimer himself admits* that, in the winged insect which he found in galls, he 

 noticed a constriction on the under side of the tarsus, though he is unwilling to allow that it was 

 a joint, because there was no motion. But even if the 2-jointed character of the more perfect 

 ouse were not demonstrated, all the other characters are so unmistakably Aphidian that there is, 

 we think, no warrant in making a new family. In such degraded insects, where the antennal 

 joints are so variable, we might naturally expect to find variation in the joints of the legs. The 

 more familiar we become with the biological secrets of Nature, the more do we find, not only spe- 

 cies but genera, and even families, approaching each other through modifications found in indi- 

 viduals ; and these aberrant gall-lice only help to give us a better idea of the close connection be- 

 tween the Coccidce and Aphida. Our Phylloxera brings the two families close together, by its affin- 

 ities on the one side with Chermes of Linnaeus, which, though looked upon as a Coccid by Ratze- 

 burg, is generally considered an Aphidian, and on the other with the Coccidan genus Dactylrpius 

 which contains Linnaeus's Coccus adonidum. The oviparous nature of these gall-lice will also have 

 less significance when we reflect that there is a sort of gradation in this process, and that many 

 Plant-lice which are considered viviparous or ovoviparous do in reality bring forth their young 

 enveloped in a more or less distinct egg-like film or covering, from which they have to free them- 

 selves by a process analogous to that of hatching. This has not only been observed by Curtis, in 

 the case of an Aphis found on the turnip, f but by Dr. Win. Manlius Smith, of Manlius, N. Y .,% in 

 the case of Pemphigus ; but we have, the present year, assured ourselves of the accuracy of Dr. 

 Manlius's observation as to Pemphigus, and witnessed the same thing in Eriosoma, namely in E. 

 pyri, Fitch. In this last case the newly deposited louse (or egg) remains motionless for a conside- 

 rable time; and the covering, after the young louse has extricated itself from it, may be as dis- 

 tinctly saen attached to the end of its body as the covering or egg-shell of our Grape gall-louse, 

 and was figured by Fitch, who mistook it for the cotton-like matter, which, however, is not secre- 

 ted till the louse fastens itself and begins to grow.g Moreover those Aphidians which are vivipa- 

 rous through the spring and summer months, generally lay eggs in the fall : ami though agamous 

 and viviparous multiplication can be prolonged by submitting the lice to a continued artificially 

 temperature, there is doubtless a limit to this prolongation; and it may be laid down as a 

 rule that, with most Aphidians, the tf element and the production uf eggs are, at some time or 

 other, indispensable to the continuance of the species. 



- of a Supposed New Family.. ; 

 ■ ts, p, 05. 



ctore Walsh, P. E, S. P. VI, p. 2S2, note. 

 .V V. Rep. I, p.y. 



