480 
MR. W. H. CALDWELL ON THE EMBRYOLOGY 
XII. The delicate layer immediately surrounding the ripe ovum, known as the 
“ true vitelline membrane,” Van Beneden, is perhaps the first stage of 
the substance described as “ coagulum ” in Monotremata and Marsupialia. 
List of Works referred to/" 
Monotremata. 
1. Baer, K. E. von. Noch eine Bemerkung liber die Zweifel welche man gegen 
die Milchdrlise des Ornitborhynchus erhoben hat, und Betrachtungen liber das 
Eierlegen und Lebendiggebiiren. Meckel, Archiv, 1827, pp. 568-576. 
2. Beddard, F. E. Remarks on the Ovary of Echidna. Edinburgh, Phys. Soc. 
Proc., vol. 8, 1885, p. 354 (Plates XVI. and XVII.). 
3. Bennett, George. [On the _ Mammary Secretion of Ornithorhynchus^] Zool. 
Soc. Proc., Part 1, 1833, p. 82. 
4. Bennett, George. Notes on the Natural History and Habits of the Ornithorhyn- 
chus paradoxus, Blum. Zool. Soc. Trans., vol. 1, 1835, pp. 229-258. (Plate.) 
5. Bennett, George. Notes on the Duck-Bill ( Ornithorhynchus anatinus). Zool. 
Soc. Proc., Part 27, 1859, pp. 213-218. (Plate.) 
6. Bennett, George. Gatherings of a Naturalist in Australasia. London, 1860.— 
(Chap. vi. and vii. ; pp. 94-150.) 
7. Bennett, George Frederic. Notes on Ornithorhynchus paradoxus, in a letter 
from Dr. G. Bennett to Sir R. Owen, with remarks by the latter. Zool. Soc. 
Proc., 1877, pp. 161-166. 
8. Bennett, George Frederic. Observations on the Habits of the Echidna 
liystrix of Australia. Zool. Soc. Proc., 1881, pp. 737-739. 
9. Blainville, H. M. D. de. Dissertation sur la Place que la famille des Ornitho- 
rhynques et des Echidnes doit occuper dans les Series naturelles. Paris, 
1812. 
10. Blainville, IT. M. D. de. Memoire sur la Nature du Produit femelle de la 
Generation dans rOrnithorhynque. Paris, Mus. Hist. Nat. Nouv. Ann., 
vol. 2, 1833, pp. 369-416. (Plate.) 
11. Blainville, H. M. D. de. Lettre au sujet de rOrnithorhynque, adressee a 
l’Editeur de ‘ L’Lcho du Monde,’ 1835. 
12. Blumenbach, J. Fr. Ueber das Schnabelthier (Ornithorhynchus paradoxus), ein 
neu-entdecktes Geschlecht von Saugethieren des funften Welttheils. Voigt, 
Magazin, vol. 2, 1800, pp. 205-214 ; Gottingische Anzeigen, vol. 1, 1800, 
p. 609. 
13. Blumenbach, J. Fr. Einige anatomiscke Bemerkungen liber den Ornithorhynchus 
* For general list of works on Monotremata and Marsupialia, see tlie excellent catalogue by 
J. J. Fletcheb, ‘New South Wales, Linn. Soc. Trans.,’ 1885. 
