ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 145 



limited to one part or organ. The final result of development is not 

 due to the independent action of various factors and their products, but to 

 the combined action, or the interaction of these products. The normal 

 development of the wing is influenced by many factors, as is suggested 

 by data derived from the various wing-mutations in this fruit-fly. One 

 factor is responsible for miniature wings, another for vestigial, another 

 for rudimentary, another for curved, and so on. 



Early Stages of Paltostoma schineri.* - - H. Scott describes the 

 larva? and pupae, recently found in Trinidad, of Paltostoma schineri, 

 one of the remarkable family of Blepharoceridge or " net-winged midges." 

 The species has hitherto been described from the male sex only. Female 

 larvaa and pupas are now described for the first time. The larva has 

 short two-jointed antennas ; dorsal surface spinose ; branchial filaments 

 arranged in tufts : lateral processes simple, pediform, ciliate, without 

 long setas ; sixth segment with only one pair of lateral processes. In 

 the full-grown larva there are ten branchial filaments, arising in five 

 pairs, in each tuft. In the half -grown larva the number is much less. 

 A similar increase during growth has been observed in Liponeura. The 

 larvae and pupas, described as those of the South African Kellogina 

 barnardi, do actually belong to that species, in spite of doubts expressed 

 on that point. The larvae of Kellogina and Paltostoma have a number 

 of points of resemblance, and both differ from Gurupira in the arrange- 

 ment of the branchial filaments. But in the possession of spines 

 Paltostoma approaches Gurupira. The pupa of Paltostoma schineri is 

 characterized by the large number of erect spiniform hairs on its dorsal 

 surface. The mouth-parts of the male conform to the general Ble- 

 pharocerid type, but are characterized by extreme length and slenderness 

 of labrum, hypopharynx, and labium, and by extreme reduction of the 

 palpi, which are minute and at most two-jointed. The female has a 

 much shorter, stouter proboscis, and palpi normally developed. 



The paper includes a full description of the female imago by C. G. 

 Lamb. 



5. Arachnida. 



Life-cycle of a Spider.f — Jeanne Berland has made a study of 

 Uloborus plumipes, a cribellate spider. It is a sun-loving creature, 

 making a horizontal orbicular web between the Opuntia-stems at Banyuls- 

 sur-Mer. When disturbed, it pays out a thread and sinks to the ground, 

 where it is difficult to detect. Each ivory-white cocoon contains about 

 fifty eggs, and is sedulously watched by the mother. The hatching was 

 observed under a binocular, and the first moult, which immediately 

 ensues. A compact group of young spiders remains around the empty 

 cocoon for some days. The observer fed two hundred for six months 

 first with Aphides and then with fruit-flies {DrosophUa) whose legs had 

 to be removed. 



The young spiders make circular webs adjacent to one another, and 



* Ann. and Mag. Nat. Hist., xv. (1915) pp. 181-202 (3 pis.) 



t Arch. Zool. ExpSr., liv. (1914) Notes et Eevue, No. 3 pp. 45-57 (9 figs.). 



