Certain Aphididæ contain a strongly irritating substance which produces, not merely on mucous membranes but on outer skin, a characteristic inflammation.
It has been frequently reported that the larvæ of the European cabbage butterfly, Pieris brassicæ, accidentally eaten by cows, horses, ducks, and other domestic animals, cause severe colic, attempts to vomit, paralysis of the hind legs, salivation, and stomatitis. On postmortem there are to be found hæmorrhagic gastro-enteritis, splenitis, and nephritis. Kobert has recently investigated the subject and has found a poisonous substance in the blood of not only the larvæ but also the pupæ.
FOOTNOTES:
[A] This is diametrically opposed to the findings of Bordas (1905) in the case of the European Latrodectus 13-guttatus, whose glands are "much larger than those of other spiders." From a considerable comparative study, we should also unhesitatingly make this statement regarding the glands of our American species, L. mactans.
[B] Dr. E. H. Coleman (Kellogg, 1915) has demonstrated its virulence by a series of experiments comparable with those of Kobert.
[C] According to Stiles, the species occurring in the Northwest which is commonly identified as D. venustus should be called D. andersoni (see footnote, chapter 12).
[D] It should be remembered that in all the higher Hymenoptera the first abdominal segment is fused with the thorax and that what is apparently the sixth segment is, in reality, the seventh.