14 



PSYCHE. 



[January — February i5 



EGG-LAYING OF LIMENITIS DISIPPUS. 



On 12 Julj, in Sugar Hill, N. H., I saw a 

 female Limenitis disippns fljing heavily over 

 a bank bj the roadside. This bank was 

 covered with young poplar shoots, and, see- 

 ing the butterfly settle on one of these, I 

 followed her, and saw that she laid an e.^^ 

 on the tip of a leaf and then flew away. 

 Picking the leaf, I followed her to the next 

 shoot which she selected, and continued the 

 chase until I had collected seventeen eggs. 

 Then the butterfly rose higher in the air, 

 flew to an ash-tree, and was hidden in the 

 leaves. A shower was near, and rain began 

 to fall in less than five minutes after she dis- 

 appeared. 



The eggs all hatched in due time, and pro- 

 duced eleven males and six females, all per- 

 fect. 



One peculiaritj' of this female was that she 

 laid more than the "one egg at the very tip," 

 which books and pictures have led us to ex- 

 pect. 



One leaf had four eggs ; one at the tip, two 

 on one edge near the tip, and one on the 

 other edge near the tip. Another leaf had 

 two; one on the tip, the other near it. The 

 third leaf had three irregularly placed near 

 the tip. 



Afterwards I found four eggs, two on each 

 side of the tip of a willow-leaf, but these were 

 not near the same place, and were the only 

 eggs of Z,. disiffus that I found on willow. 

 I found no larvae on willow, while they were 

 very abundant on poplar shoots close by. In 

 fact L. disippus was more abundant this sum- 

 mer than I have ever found it before. 



Caroline G. Soule. 



A SPHAERULARIA-LIKE WORM. 



In the American naturalist for January, 

 1886 (v. 20, p. 73-75), I called attention to 

 some of the peculiarities of Sphaerularia 

 bombi, a nematod parasitic internally in spe- 

 cies of bumble-bees {Bo?nbus), and to the 

 fact that a species of Sphaerularia was 



found in America. One remarkable pecul- 

 iarity of Sphaerularia is that the genital 

 organs of the female evaginate, and form, 

 when they have attained their full size, a 

 worm-like body. The evaginated ovary is so 

 large in proportion to the worm itself, that 

 the latter was, for a time, overlooked by nat- 

 uralists, and the evaginated portion was 

 described as a worm. 



Professor R. Leuckart, whose researches 

 have done much towards completing our 

 knowledge of the life-history of Sphaerula- 

 ria^ has published, in the Zoologischer an- 

 zeiger (20 Dec. i886, v. 9, p. 743-746), a 

 preliminary communication entitled, "Ein 

 spaerulariaartiger neiier nematode," in which 

 he gives an account of the structure and 

 habits of a nematod allied to Sphaerularia, 

 to which he gives the name of Asconema 

 gibbosum. This worm was discovered in 

 the body-cavity of Cecidomyia pint, even in 

 the larval state. The worm is about 0.6 mm. 

 long, and the adult female bears, upon the 

 ventral surface near the posterior extremity, 

 a bean-shaped process about 0.25 mm. long. 

 The digestive tract does not form a tube in the 

 adult, but is reduced, as it is in Sphaerula- 

 ria, to a chain of large cells. 



The eggs of Ascotiema fall into the body- 

 cavity of their host, the Cecidomyia, where 

 they hatch, but the young do not reach their 

 sexual development until they are set free 

 from the host, by the death of the latter. 

 Sexual union takes place within a few days 

 after the Asco7iema are free from their 

 host. After this the males die and the 

 females that get the opportunity pass into 

 the Cecidomyia larvae, which inhabit soil 

 composed of decaying pine-needles. Again 

 in the body-cavity of a Cecidomyia, the 

 female develops and evaginates its genital 

 organs, while the digestive tract becomes 

 rudimentary. The ovaries of Asconema are 

 not so large as those of Sphaerularia ; while 

 the latter worm requires a year for its devel- 

 opment, Asconema develops in a few weeks. 



G : Dimmock, 



