18 SUMMARY OF CURRENT RESEARCHES RELATING TO 
Artificially produced Cauda bifida.* * * § — Herr D. Barfurtli points out 
that the spina bifida and cauda bifida which have been often produced 
artificially are rather due to imperfect coalescence ( asyntaxia medullaris 
and asyntaxia caudalis') than to a literal bifurcation. But the latter 
does occur in nature in Lacerta , Yaranus, Petromyzon Planeri, &c., and 
he has been able to produce it artificially in tadpoles of Bana fusca, by 
wounding them with a blunt hot needle in the mid-dorsal line of the 
median portion of the tail, and then amputating the posterior portion. 
The result in many cases is that from two regeneration centres a bifid 
tail grows out. 
Foetal Development of the Glomus coccygeum.f — Herr J. H. 
Jakobsson finds that this structure (so-called Steissdr'iise) appears in a 
human foetus of 15 cm. in length (end of fourth month) as an oval clump 
of epithelium-like cells bounded by a capsule of connective tissue strands, 
and connected by numerous fibres w r itli the sympathetic. Later on, 
connective tissue predominates in the organ, which also becomes very 
vascular and lobulated. But its origin is certainly not in the connective 
tissue, nor from medullary canal, notochord, or rectum. It is in all 
probability derived from the end of the sympathetic, with which it is 
from the first closely connected. 
Share of the Ectoderm in Forming the Pronephric Duct. — Prof, 
van Wijlie J reaffirms the conclusion which he reached some years ago,, 
that the ectoderm shares in the development of the pronephric duct of 
Selachians ( Scylliurn , Baja , &c.) — a conclusion from which Babl, who 
once agreed, has since vigorously dissented. Van Wijhe’s conclusion 
rests upon two facts : the coalescence of the caudal end of the growing 
duct with the epidermis, and the position of the dividing nuclei, which 
are so disposed that one daughter-nucleus must go to the “ Anlage ,y 
(primordium) of the duct, while the other remains in the epidermis. 
Miss E. R. Gregory § has also observed in embryos of Acanthias, 
that when the pronephric duct begins to grow backwards, there is a 
coalescence between its end and the ectoderm. 
Sex in a Brood of Sparrow-hawks.|| — Dr. R. W. Schufeldt found 
that in a brood of five young sparrow-hawks examined by him, the sexes 
of the nestlings alternated regularly, the oldest being a male, the next 
a female, and so on. From the relative sizes of the birds he inferred 
that the eggs had been laid at regular intervals, probably of three or 
four .days, and that incubation had begun as soon as the first egg was 
laid. He makes no suggestion as to the interpretation of the alternation 
of sex. 
Syncytia in Development.^ — Prof. W. His publishes a' very im- 
portant paper on syncytia, that is, “ complexes of mutually connected 
histological units or plasmockores, which are distinctly separated from 
* Verh. Anat. Ges. xii. Vers., in Anat. Anzeig., xiv. Erg.-lift. (1898) pp. 21-6. 
f Arch. Mikr. Anat., liii. (1898) pp. 78-106 (2 pis.). 
t Verh. Anat. Ges. xii. Vers., in Anat. Anzeig., xiv. Erg.-hft. (1898) pp. 31-7 
(7 figs.). 
§ Zool. Bull., i. (1897) pp. 123-9 (8 figs.). See Biol. Centralbl., v. (1898). 
pp. 817-8. || Amer. Nat., xxxii. (1898) pp. 567-70 (1 fig.). 
H Abhandl. k. Sachs. Ges. Wiss , xxiv. (1898) pp. 401-68 (41 figs.). 
