Volume 4, Issue 6
December 1936, pages 435-516
pp 435-453 December 1936
pp 454-470 December 1936
The above description of the male genitalia of some of the important forms belonging to Amblycera and Ischnocera, infesting Indian birds, shows in some degrees the extent of variation and modification undergone by the biting-lice in their male genital structures. It will also serve to emphasise the importance of the male genitalia in the taxonomic study of Mallophaga of both the above mentioned sub-orders. The study of homologies of the various structures is a difficult task until the development of male genital armature has been followed in important groups. Yet the author believes that for the time being they can be persued along the lines of Ewing who has studied the male genitalia of Anoplura or the sucking-lice.
Another inference which can be derived from the above study of the male genitalia of Amblycera and Ischnocera is that in the Amblycerans the male genital structures are of more generalised type and have gone less modification, whereas in Ischnocera we find that the male genitalia are much specialised along various divergent lines.
pp 471-482 December 1936
Arenaria musciformis.—A lenticular generative cell is organised in the 2-nucleate pollen grain. The ripe pollen grain in the anther is either 2-nucleate or 3-nucleate and the two male nuclei are spherical in form but unequal in size. A fully-formed embryo-sac is, as usual, 8-nucleate and of the normal organisation.
Thylacospermum rupifragum.—A definite generative cell is formed in the 2-nucleate pollen grain. The ripe pollen grain in the anther is invariably found to be only 2-nucleate. A fully formed embryo-sac differs from the normal one ofArenaria mainly in the structure of its egg-apparatus— the synergids possess lateral hooks and exceed the egg in the size of the cell. In the seed, the embryo, lying curved on one side of the perisperm, is embedded in a complete sheath of endosperm, two to four cells thick.
A marked feature of the life-histories ofArenaria andThylacospermum is the large amount of degeneration in both the pollen grains and the embryo-sacs.
pp 483-493 December 1936
In the present study, observations have been made on a polymelous specimen ofRana tigrina Daud., the first abnormality of this type recorded for this species. Not only is a complete description of the external features given, but an examination of the correlated abnormalities in the muscular, skeletal and nervous systems has also been made. Apparently, the supernumerary right fore-limb shows a reversed condition to that found in a normal right fore-limb in this species.
pp 494-513 December 1936
pp 515-515 December 1936 Erratum
pp 516-516 December 1936 Erratum