ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 215 



Regeneration of Lost Parts.* — Herr V. Wagner discusses the 

 intimate nature of the processes which take place when a spider regene- 

 rates a lost appendage. He describes in order the formation of the 

 chitinous knob, the atrophy of old tissues, the growth of the new part. 

 His general results are the following : — (1) The blood-corpuscles meta- 

 morphose to give rise to a tissue resembling chitin. (2) The fatty 

 degeneration of the old tissues benefits the organism in three ways — 



(a) by supplying material to be digested and utilized by amoeboid cells ; 



(b) by supplying matter to be absorbed by the coloured blood-corpuscles ; 



(c) by the direct benefit of the diffusing fatty globules. (3) Without 

 the blood-corpuscles the process of regeneration probably could not 

 occur. (4) The process of degeneration in the muscular tissue of 

 spiders is, in general terms, like that which occurs in vertebrates. 

 (5) The integument, matrix, and subcutaneous layer of connective tissue 

 do not arise from new elements, but the old non-atrophied tissues grow 

 with peculiar power in good nutritive conditions. The spider must be 

 tolerably young — that is, have some few moults before it — if the appen- 

 dage is to be wholly renewed. The lost organ is replaced in the period 

 of time between two successive moults at the stage of development at 

 which it was lost. The palp cannot be completely regenerated if it 

 is lost late — that is, when the copulatory apparatus has arisen. 



Age and Habits of American Tarantula.f — Dr. H. C. M'Cook 

 commences with a tragic account of the death of Sir J. Lubbock's aged 

 ant-queen, which, in the course of last year, attained the age of thirteen 

 years ; but he concludes with the publication of a note from Sir John, 

 saying that in January 1888 the " venerable sovereign of the emmet 

 world," as Dr. M'Cook calls it, was still alive. Passing to his proper 

 subject, Dr. M'Cook records the death of a specimen of Tarantula which 

 had been in his possession for more than five years, and which was 

 certainly seven and may have been eight years old. He ascribes its 

 great longevity partly to human protection. With regard to its habits 

 the author observes that the act of moulting is frequently attended with 

 danger of some kind or another to spiders. To keep spiders alive, it is 

 better to underfeed than overfeed them, but they must always have a 

 supply of fresh water, and should be kept at a moderate temperature. 

 In spinning, the animal slowly moved its whole body round as upon a 

 pivot, and so dispersed the silk over a circular patch. The only nest 

 of the Tarantula is a burrow in the ground, and it does not, as is often 

 supposed, make any trap-door. There are interesting notes on toilet- 

 habits and on the character of the egg-cocoon. 



Distribution of Arachnida.J — Two years ago, Prof. 0. Zacharias 

 discovered in the little Iser a new species of Hydrachnida, which Herr 

 F. Kornke named Sperchon glandulosum. He writes now to note the 

 fact that at a similar elevation (800 metres above the sea), and in similar 

 conditions in the Azores, the same species is, according to Barrois, quite 

 abundant. As it is very rare in Germany — never found, in fact, except 

 in the first locality — this further discovery is interesting. 



* Bull. Soc. Imp. Nat. Moscou, i. (1887) pp. 871-99 (1 pi.), 

 t Proc. Acad. Nat. Sci. Philad., 1887, pp. 369-86. 

 X Biol. Centralbl., vii. (1887) pp. 631-2. 



