ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
287 
The phenomena of their origin, and their relation to the secondary 
asters, are similar to those described by Reinke in the tissue-cells of the 
larval salamander. 
Regeneration and Autotomy in Earthworms.* * * § — Herr K. Hescheler 
made experiments in 1896 which showed that (in Lumbricus Herculeus , 
L. rubellus, Allolobophora foetida, All. caliginosa, All. terrestris) the rege- 
neration of a lost anterior end only occurred within narrow limits. 
When more than ten segments are lost, the regeneration decreases 
rapidly in completeness, and in most cases only four or five new seg- 
ments are formed. Morgan got similar results; but Joest and Korschelt 
reported extraordinary regenerative pow’er, far exceeding what Hescheler 
observed. As further experiments have confirmed Hescheler in his 
results, he suggests, in explanation of the discrepancy, that Joest and 
Korschelt must have worked with different species. 
Hescheler has also shown that autotomy ( Selbstamputation ) occurs in 
the posterior region of Lumbricus Herculeus , L. rubellus , Allolobophora 
foetida , All. clilorotica, All. caliginosa , All. terrestris , and All. cyanea . 
It is a general, habitual, and adaptive phenomenon, which may be in- 
duced by discomfort, by mechanical, chemical, and electrical stimuli, and 
in dying. The author compares what occurs in earthworms with obser- 
vations on Nephthys scolopendroides and Clisetopterus. What is limited 
in Lumbricus and Allolobophora is more pronounced in Allurus, and 
yet more so in Criodrilus , while Lumbriculus is reproduced by fission 
at certain seasons. 
New North American Oligochseta.f — Mr. Frank Smith describes 
from the Illinois river, at Havana, a new Naidomorph Pristina leidyi 
sp. n., closely allied to P. longiseta Ehrenb. ; also Mesoporodrilus asym - 
metricus g. et sp. n., in some important respects allied to Eclipidrilus 
frigidus Eisen. A Florida collection yielded Microscolex hempeli sp. n., 
which combines characters that seem to bring the genera Phododrilus 
and Leltania very near together, and to emphasise the necessity of com- 
bining them with Microscolex , as Beddard has done. In a previous 
paper J the author described Thinodrilus inconstans g. et sp. n., a new 
Lumbriculid. 
New 01igochgeta.§ — Dr. W. Michaelsen describes Prof. Kukenthal’s 
collection from Halmahera, Ternate, Borneo, &c. It includes among 
Oeoscolecidae Glypliidrilus KueJcenthali sp. n., and among Megascolecidae 
Pleionog aster ternatse sp. n. and seven new species of Perichseta. Among 
these there seems to be much variability ; thus no fewer than six sub- 
species of Perichseta halmaherse are distinguished. 
Heart-Body of Enchytrseidse.fl — Prof. J. Nusbaum and Herr Jan 
Rakowski have studied the structure of the dorsal vessel and the so-called 
Herzkorper in Fredericia and Mesenchytrseus, and conclude that the 
u heart-body ” is derivable from the blood-gland known in other Enchy- 
trmidse. The similarity of the histological characters and the similarity 
* Vierteljahrschr. Nat. Gesellsch. Zurich, xlii. (1897) pp. 51-61. 
f Bull. Illinois Lab. Nat. Hist., iv. Art. 11, pp. 396-113 (1 pis.). 
% Tom. cit., pp. 285-97. 
§ Abli. Senckenberg. Gesellsch., xxiii. (1897) pp. 193-213 (1 pi., 1 fig.). 
{| Biol. Centralbl., xvii. (1897) pp. 260-6 (1 figs.). 
