358 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Dreyfus and others have demonstrated in Chernies, &c. From the vivi- 
parous root-inhabiting form two series of descendants spring (a) The 
winged “ sexiparous ” or “ pupiparous ” form which in autumn returns 
to the elms and bears the sexual generation, and ( b ) an apterous series 
whose members remain on the roots and remain viviparous. 
Larvae of Parasitic Bees.* — Herr C. Verhoeff describes the rela- 
tions between the larvae of Osmia leucomelsena and those of the parasitic 
Stelis minuta. The mother Stelis lays its egg, before the mother Osmia, 
more or less deeply in the ball of food. The parasitic larva is hatched 
a little earlier than its victim. Both feed for a time on the food-ball 
from opposite ends. Gradually the parasite approaches the other larva, 
which it kills and eats. The Stelis- larva is then about twice the size of 
its victim. Herr Yerhoelf watched the unequal combat, and describes it 
in detail. The parasite first destroyed the brain, and sucked it for half 
a minute ; it then bit the middle of the body and sucked that. Some 
other equally interesting facts are noted. 
Passive Stage in Development of (Estridse.f — Prof. F. Brauer dis- 
cusses the period of remarkably slow growth which occurs in the life- 
history of some larval (Estridte. Thus, in Hypoderma Diana eight 
months may elapse between egg-laying and the appearance of larvte in 
the epidermic cells. The same is true of Cephenomyia, whose life-history 
Dr. J. Csokor has recently helped to elucidate. Brauer recalls his 
discovery that the eggs of (Estromyia, &c., are not laid in the skin which 
the mother-insect was supposed to perforate with her ovipositor ; they 
are laid on the skin or hairs, and the newly hatched larva bores its own 
way into the dermis. In the larva of (Estromyia the mouth-parts are 
much stronger than in the larval Hypoderma, and there is no passive 
stage. The observations of Cooper-Curtice on the ox- warble ( Hypoderma 
lineata) of the United States are of much importance, and are discussed 
at length. The American observer found 200 larvae in the oesophagus, 
45 in the “ first skin-stage ” in the dermis, 150 in the second skin-stage, 
and 550 in the third. It seems that the new-born larvae are licked off 
the skin, and occur normally iy the oesophagus and in other internal 
parts, whence they probably find their way to the skin. 
Ants and Plants.^ — Herr O. Warburg proposes to call myrmeco- 
philous plants “ myrmecophytes,” and also coins the words “ myrmeco- 
symbiosis” and “ myrmeco-symbiotic.” He divides myrmecophytes into 
“ myrmecotrophic ” forms which supply food to the ants, myrmeco- 
domous forms which offer only shelter, and myrmecoxenous which 
afford both. 
The author gives a convenient account of recent investigations, and 
discusses some special points. Thus, his observations on species of 
Myristica show that these plants are in an indirect way myrmecotrophic, 
for colonies of Aphides are kept in the cavities of the twigs; but as it 
is far from evident that the ants are in this case of any use, it is not 
justifiable to call Myristica myrmeco-symbiotic. It possibly represents 
a first stage towards a mutual partnership. 
* Zool. Anzeig., xv. (1802) pp. 41-3 (1 fig.). 
t Verb. K. K. Zool.-bot, Ges. Wien, xlii. (1892) pp. 79-84. 
+ Biol. Centialbl . xii. (1892) pp. 129-42. 
