MORPHOLOGY OF THE ALEYRODIDiE. 3 
jugeai y vouloir faire ses oeufs; je marquai l'endroit de la feuille ou il etoit. 
Je trouvai, le lendemain 26. le papillon dans la meme place ; le 27. il n'en avoit 
pas change, mais tout aupres de lui il y avoit un petit espace il peu pres circu- 
laire, aise a distinguer du reste de la feuille; il etoit poudre d'une poudre 
blanche, de celle qui blanchit toutes les parties de ce papillon; la elle eteignoit 
la vivacite du verd. Cet espace avoit environ une ligne de diametre. Sur sa 
circonference j'observai trois petits corps que je crus etre des oeufs, & qui en 
gtoient reefleinent. Enfin le 28. le papillon s'etoit eloigne d'un derai pouce au 
plus de la place ou je l'avois toujours trouve pendant les jours prec4dens. II 
me fut plus aise alors d'observer sans crainte de l'inquieter, les petits corps 
qui etoient arranges autour de la circonference du petit espace qu'il avoit 
blanchi. Avec le secours d'une forte loupe, je reconnus que leur figure etoit 
asses semblable a celle des oeufs ordinaires, elle tenoit pourtant plus de la 
cylindrique. Ces oeufs sont oblongs, ce sont de petits cylindres dont les deux 
bouts sont amenes en pointes arrondies; leur plus grand diametre etoit a peu 
pres dirige vers le centre de l'espace circulaire. 
In American literature Dr. Britton appears to have given the first 
account in 1902, though Davis mentions it in Insect Life, Volume VII, 
1894. In describing the habits of a species on lettuce, Dr. Britton 
says : 3 
The female first thrust her beak into the leaf and depositing an egg swung 
about with her beak still inserted and serving as a pivot, continuing to deposit 
eggs in a circle of about one millimeter in diameter. One of these circles con- 
tained six, while another had nine eggs. 
The same habit was described and figured by Dr. Back 4 for 
Aleyrodes howardi Quaintance, and it has been described in connec- 
tion with the description of species by the senior author and other 
writers. Some species, however, use no definite arrangement but 
scatter the eggs irregularly over the leaf almost exclusively upon 
the underside. The number of eggs deposited seems to be fairly 
large if the proper food conditions are found. Dr. Zehntner 5 gives 
150 to 200 eggs for Aleyrodes oergi Signoret, and Morrill and Back 6 
have secured 211 from a female of Aleyrodes citri Kiley & Howard. 
Dr. Morrill was the first to note parthenogenesis in this family 7 
and we give therefore his original observations on the subject 7b . 
Adult females have been isolated on plants previously free from Aleyrodes in 
any stage, for the purpose of determining the duration of adult life, the number 
of eggs laid by each female, whether or not parthenogenesis occurs, and, if so, 
its character. The females isolated for the purpose of these observations were 
seen to emerge from their pupa cases, and consequently there was no possibility 
of their having been fertilized. The plants upon which these females were kept 
.were growing in small pots covered with lantern chimneys, which were closed 
at the top with cheesecloth. Four trials were made : 
1. April 3, 1902, an unfertilized female began egg laying, and on April 17, 
three eggs were observed to have hatched. 
2. April 17, 1902, an unfertilized female began egg laying, and on April 29 
several eggs had hatched. 
3. Dec. 8, J 902, a female emerged, was isolated on a tomato plant, and began 
egg laying Dec. 12 (females usually begin egg laying on the second or third 
