GIG 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Respiration in Amphibia during 1 Metamorphosis.* — Herr F. Maurer 
gives an interesting description of the vascularisation of the epidermis 
at the time of metamorphosis in liana , Bufo, and Hyla. He finds that, 
when the skin-glands begin to develop, there appears between epidermis 
and corium a sub-epidermal layer remarkable for its numerous capil- 
laries. These capillaries grow outwards, penetrating to immediately 
beneath the outermost row of epidermal cells, so that the epidermis 
becomes completely vascularised. Other experiments have convinced 
the author that at the time of metamorphosis neither gills nor lungs are 
actively respiratory. He therefore regards this temporary development 
of superficial blood-vessels as a proof that the skin is then the main 
respiratory organ. The capillaries become much less conspicuous as 
soon as the metamorphosis is over. 
Multiple Canals in Spinal Cord of a Chick Embryo.t—-Miss A. 0. 
Smith describes the spinal cord of a chick of about ten days’ incubation. 
The embryo was normal except as regards the cord, which showed a 
series of secondary neural canals, or more properly vesicles. They did 
not open into one another nor into the central canal. All of them were 
lined with the same kind of cells as those lining the central canal, of 
which they were probably disconnected outgrowths. 
Development of Sphenodon.J — Dr. Arthur Dendy briefly sum- 
marises the more important results of his investigations on this subject. 
He finds that development lasts about thirteen months, the eggs being 
laid in November and hatched in the December of the next year ; but 
the earlier stages are rapidly passed through, and it would seem that de- 
velopment is virtually suspended during the winter months. There are 
several peculiarities in the formation of the amnion, notably in the 
presence during the early stages of a “ posterior amniotic canal,” quite 
similar to that described by Mitsukuri for Chelonians. This would 
seem to confirm the belief that Sphenodon is related to that group. 
The parietal eye apparently arises independently of the epiphysis, and 
the author is of opinion that the pineal gland is represented by a mass 
of convoluted tubules lying in front of the parietal eye. A similar 
independence of parietal organ and epiphysis has been maintained by 
Beraneck for Lacerta and Anguis. 
Regeneration in Erog-embryos.§ — Miss E. F. Brynes finds that 
tadpoles develop normal full-sized limbs, even if the limb-rudiment is 
completely destroyed at the time when it first appears. Three species 
were experimented on, Rana sylvaiica , R. palustris , and R. virescetis, and 
in all cases fresh limb-rudiments developed from the surrounding somato- 
pleural tissue. The author considers that the experiment adds fresh 
evidence to the view that the entire limb is somatopleuric in origin. 
b. Histology. 
Ganglion-cells. || — Dr. Rohde has extended his researches on this 
subject to cover the ganglion -cells of Vertebrates, and in the present 
* Morph. Jahrb., xxvi. (1898) pp. 330-6 (1 fig.). 
f Anat. Anzeig., xv. (1898) pp. 56-60 (6 figs.). 
% Proc. Roy. Soc. Lond., lxiii. (1898) pp. 440-3. 
§ Anat. Anzeig., xv. (1898) pp. 104-7 (3 figs.). 
|| Zeitschr. f. wiss. Zool., lxiv. (1898) pp. 697-727 (5 figs.). 
