652 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVI. 



percantage of oxygen available to the plant in different media, may be 

 shown to evidence by the examination of a pneumatophore of Avicennia 

 officinalis. The respiratory root is very thin at the base, where 

 it is covered by mud ; it grows thicker, where it is submerged in water, 

 and it reaches its maximum, where it is surrounded by the atmosphere. 

 And if we examine the anatomical structure, we find that the various 

 degrees of thickness are due to the respective development of the par- 

 enchymatous tissue, which contains the lenticels, i.e , the respiratory 

 organs, The same may be observed in the species of Khizophora. 

 They are not possessed of special pneumatophores, but the modified 

 tissue of their " stilt roots " takes upon itself the function of respiration, 

 and here agiin it is not the portion buried in the mud, but the one 

 emero-inof from the mud and still more the upper part which is accessible 

 to the atmosphere. 



Alone the muddy sea-coasts of the Konkan grows Carapa obovata, Bl. 

 (Mel'iacase), a small glabrous tree. The abruptly pinnate leaves are 3 to 6 

 in. lono- with oblong-ovate, glabrous, coriaceous leaflets. The fruit has 

 the size of an orange, 3 to 4 in. in diameter. When young it is apiculate. 

 The flashy pericarp dehisces by four valves. The angular seeds are sur- 

 rounded by a hard spongy testa. 



The pneumatophores of this plant show great resemblance to those 

 of the Bruguieras ; but, whereas in the latter we have those knee-like 

 structures and, consequently an up-and downward growth of the roots, 

 we observe that the roots of the former creep horizontally just under 

 the surface of the muddy substratum and send above the surface of it a 

 wedge-shaped expansion of the upper half-cylinder, which, on the top, 

 is covered with a great number of lenticels. 



In the South Konkan along salt-water creeks and backwaters a tall 

 glabrous shrub or small tree makes its appearance, Lumniizera racemosa, 

 Willd. Its entire or slightly crenate, sessile leaves are fleshy, coriace- 

 ous and crowded at the ends of the branches. The glabrous calyx of 

 the sessile flowers has the teeth ciliolate. The ovoid, glabrous fruit is -| 

 in. lono- with longitudinal strise when dry and the persistent calyx-tube 



at the top. 



A handsome shrub with laurel-like appearance and growing in salt- 

 marshes, together with the different kinds of mangrove, is Mgiceras 

 majus, Gaertn. (Myrsinaces). The cylindric branches bear obovate, 

 entire, coriaceous leaves. The umbels of the pure white fragrant flowers 



