ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 381 



being due to the fact that the primary or sternal piece of the labium and. 

 the connective membrane which unites it with the mentum are extraordinarily 

 elongated ; in consequence of this the primary piece can be protruded and 

 withdrawn through a considerable space ; the paraglossae are wanting. The 

 labial palps are remarkable for their club-shaped form, but this is not quite 

 so remarkable, as an examination of the genus Megalops would show. 

 Figures in illustration are promised in a more extensive memoir which 

 will shortly appear. 



Prothoracic Appendages of Lepidoptera.* — M. N. Cholodkovsky, re- 

 ferring to the previous communication made by Dr. Haase, allows that the 

 presence of prothoracic appendages has been noted by previous writers, but 

 he traverses the opinion of his critic that the parts in question are secondary 

 accessory structures. The justice of this criticism, and of others like it, is 

 difficult to determine, but the following facts seem to speak against Dr. 

 Haase ; structures which are morphologically of the same value appear in 

 different forms at very different stages in development, and the late appear- 

 ance of the appendage is not pro tanto an argument against their primary 

 nature; again in the development of the Squillidee we find pairs of ex- 

 tremities well developed in the Protozoea-stage, which atrophy in the zoea, 

 and again appear after metamorphosis. In position the prothoracic 

 appendages agree better with rudiments of wings than with tegulge, and in 

 structure they are not hard solid chitinous plates, as are the tegulee, but 

 soft vesicles filled with blood and tracheal branches. 



Morphology of MalpigMan Tubes in Lepidoptera.f — M. N. Cholod- 

 kovsky has studied the morphology of the urinary system of Lepidoptera 

 which turns out to be less uniform than is usually supposed. 



(a) In Tineola hiselliella, for instance, there are only two long simple 

 tubes, while in the Lepidoptera generally there are always six. In the 

 caterpillars of Tineola, however, there are six as in other Lepidopteran 

 caterpillars. On the second day of chrysalid life the six tubes exhibit 

 symptoms of degeneration. The terminal tubes gradually disappear 

 by histolysis, the basilar trunk increases, and eventually gives rise 

 to the simple urinary apparatus of the adult. The author notes the 

 probable connection of this series of changes with the abundant nutrition 

 of the caterpillar, the fasting life of the pupa, and the advantage of light- 

 ness in the adult insect. 



(6) In Galleria melonella the urinary system is represented by two 

 richly and irregularly ramified trees ; neither basilar trunk nor terminal 

 tubes nor bifurcation of a trunk into branches. A very short lateral 

 prolongation of the intestine is regarded as homologous with the 

 basilar trunk. In the caterpillar the usual six vessels are present, 

 and these disappear as above, being replaced by a secondary arbores- 

 cent growth in the chrysalis. The caterpillar devours enormous quan- 

 tities of fatty substance. It is probable that this reserve store is utilized 

 in the chrysalis phase, and the great development of the urinary vessels 

 ■would permit of the rapid elimination of large quantities of oxidized 

 material. 



(c) In the other Lepidoptera the variations are insignificant : a brief 

 summary of their peculiarities in the different families is communicated. 



(d) The embryological studies of Hatschek and Tichomirow have 

 shown that the Lepidopteran embryo has only two basilar trunks arising 

 as diverticula from the rectum. In Tineola hiselliella these are much 



• Zool. Anzeig., x. (1887) pp. 102-3. 



t Arch, de Biol., vi. (1887) pp. 497-514 (1 pi.). 



