SCIENTIFIC SUMMARY. 
325 
wished that the further development of this singular form of parasite may 
he ascertained. M. Villot states that he also finds a nematoid worm of the 
genus Cephalobus in the stomach of the Glometds, which is very common in 
the limestone mountains surrounding the city of Grenoble. 
JBeterogeny in the Gallflies . — It has been long known to entomologists 
that while of some genera of the delicate little Hvmenoptera which pro- 
duce most of the excrescences on plants known as galls, in which their 
larvae live and arrive at maturity, both males and females might always be 
reared, other nearly allied forms were only known by a single sex, none 
but females of them having ever been seen. This was strikingly the case 
with some of the Cynipidse that infest the oak ; and according to a com- 
munication made by M. J. Lichtenstein to the Entomological Society of 
Erance, Dr. Adler, of Schleswig, has devoted a good deal of attention to 
the investigation of these little insects, with most curious and interest- 
ing results. He finds that the phenomena in question constitute a case of 
heterogeny'; that is to say, the agamic genera, or those of which females only 
are known, are only transitory forms, producing galls quite different from 
those from which they themselves issued, and giving origin to both male 
and female insects. In form and structure these two successive winged 
generations of the same insects present no resemblance to one another, 
and do not even belong to the same genus. This certainly constitutes the 
most remarkable instance of “ alternation of generations ” with which we 
are acquainted. Thus the common species, Spathegaster haccarum , which 
issues from the fleshy galls, like white currants, under the leaves of 
the oak, presents male and female individuals with rather short ovi- 
positors. The females prick the young leaves, and thus give rise to galls 
quite different from those from which they emerged ; namely, the small 
lenticular or “ spangle ” galls, from which Neuroterus lenticularis proceeds. 
In the genus Neuroterus there are only agamic (female) individuals, which 
have a very long ovipositor rolled up in the abdomen. They emerge in the 
winter, and lay their eggs in the buds of the oaks in March and April, 
thereby causing the formation, not of the lenticular autumn galls, but of the 
currant-like spring galls from which the Spathegaster is produced. Thus 
both the insects and the galls are exceedingly different. Dr. Adler has 
ascertained that this relation exists between several species of Cynipidse, of 
which the following is a list : — 
Neuroterus fumipennis is the agamic form of Spathegaster albipes. 
„ lenticularis 
,, numismalis 
Dryophanta scutellaris 
„ longiventris 
Aphilothrix radicis 
Spath. haccarum. 
„ vesicatrix. 
Trigonaspis crustalis. 
Spathegaster Taschenbergi. 
Andricus noduli. 
Parthenogenesis in Ants. — In his paper on the habits of ants (“ Journ. 
Linn. Soc.,” Zool., Yol. xiii., No. 63), a short notice of which appeared in 
our last number, Sir John Lubbock refers to the occurrence of true partheno- 
genesis among those insects. He finds that, as among bees and wasps, the 
workers occasional^, although rarely, lay eggs. His observations do not 
enable him to say whether these necessarily unfertilized eggs produce males,. 
