Volume 66, Issue 2
August 1967, pages 37-73
pp 37-44 August 1967
The present study deals with the distribution and structure of floral sclereids inFagraea fragrans Roxb.,F. ridleyii K. & G. andF. ceilanica Thunb. and their ontogeny inF. fragrans. The sclereids are diffuse, branched, with thick and stratified walls, showing pits, pit canals and spicules. On the basis of form, four types of sclereids have been recognised. The development of sclereids, both in the pedicel and ovary ofF. fragrans, is similar. Distribution and structure of sclereids in sepals seem to provide a distinct and sharp demarcating character for all the three species.
pp 45-52 August 1967
The sclereids are present in the fruits and the stem of three species ofSyzygium, namelyS. cumini, S. cinereum, S. nodosum, andEucalyptus tereticornis. They are absent from the leaves of all the species. InSyzygium mostly brachysclereids occur in the stem, with a few osteo and astrosclereids in fruits. InEucalyptus there are polymorphic brachy, osteo, astrosclereids and bizarre types in both the stem and fruits. The ontogeny of the sclereids is the same in all the species. The sclereids of all these species are unusually large and the distribution pattern varies particularly in the fruits. Their structure also is different in the two genera and all this may be of some taxonomic value.
pp 53-62 August 1967
The minute anatomy of the heart ofHeteropneustes fossilis has been described. The anteriormost chamber of the heart is a bulbus arteriosus with an appendant pouch-like structure. As for the cardiac-valves, there are a pair of sinu-atrial valves, two pairs of atrio-ventricular valves and a pair of ventriculo-bulbar valves. The conducting tissues are absent in the heart.
pp 63-73 August 1967
The existence of physiologic races inPiricularia oryzae Cav., the causal fungus of blast disease, has been established in India. Sixteen races and three biotypes were distinguished out of 19 isolates tested. Three of the races correspond to races 8, 16 and 25 of the U.S.A.
Varieties likeBJ. 1,Zenith, Norin-22,Te-tep andTadukan have proved resistant to all the Indian races ofPiricularia oryzae.