Volume 57, Issue 6
June 1963, pages 339-399
pp 339-342 June 1963
Tetraploidy has been induced inCatharanthus roseus by treatment with colchicine. These tetraploids are more vigorous in their growth and have bigger flowers, larger stomata than the normal diploids.
pp 343-355 June 1963
pp 356-367 June 1963
The fully formed chondrocranium ofTylosurus crocodilus is of the tropitrabic type. A median nasal septum develops from the ethmoid plate. It is connected dorsally to the sphenoseptal commissure of the orbital cartilage. The olfactory nerve passes through a foramen olfactorium evehens. The trabeculae become discontinuous with the parachordals. A short interorbital septum is formed. The epiphysial cartilage is well developed and extends posteriorly as the taenia tecti medialis. All the three cartilaginous semicircular septa are developed. Meckel’s cartilages anteriorly form a symphysis and posteriorly they bear a retro-articular process. The hyosymplectic does not fuse with the quadrate. The basihyal is continuous with the common copula formed by the first two basibranchials.
pp 368-378 June 1963
S. conica andS. conoidea have both 2n=20 andn=10. In the former earlier work shows that it hasn=12. Both are very similar in morphology and can be recognised only on the basis of petal characters. Their distribution is sympatric. The F1 hybrid between these is healthy, vigorous and is fully fertile. Pairing is normal. It is suggested that the two be treated as varieties of one and the same species.
pp 379-388 June 1963
Experiments were conducted in cement cisterns to find out the effect of adding different dosages of activated sludge on fish growth and plankton production. Three dosages of sludge,viz., 62·5 gm., 125 gm. and 250 gm. per 240 litres of water were used. Fingerlings ofCyprinus carpio, Cirrhina mrigala andCatla catla responded positively,C. mrigala showing maximum growth. The results indicate that the sludge has a direct influence on increasing growth of fish and production of plankton due to the release of nutrients into the water. The increase in plankton content stops after about 30 days. When greater quantities of sludge were added in the cisterns, fish mortality took place.
pp 389-399 June 1963
A petrified pseudostem from the Deccan intertrappean beds, belonging to the family Musaceae is described in this paper and referred to Jain’sMusocaulon indicum. Some of Jain’s observations are confirmed and new facts not recorded by him are figured and described. The anatomy of the midrib and epidermis with stomata has been studied. These facts confirm the Musaceous affinity of the specimen and draw attention to features of resemblance between the living genusMusa and the petrified specimen.