OBSERVATIONS ON THE VOLVOCAGEAE. 



331 



the end of ifc, when its force gets more and more spent, we in Madras 

 get small showers (local showers) at very frequent intervals. 



The effect of these small intermittent summer showers is, falling 

 as they do on a parched up soil, merely to wet the surface soil and 

 to fill up the various small depressions in the ground, causing 

 numerous rain water pools all over the place. During these Summer 

 Monsoon months the water in these pools is constantly changing its 

 level. Thus after a fairly good rain the depressions are filled up. 

 During the succeeding rainless days, the level of the water goes down 

 slowly, and in the shallower depressions the water dries up completely. 

 In the deeper pools, however, where the water does not get com- 

 pletely dried up, a fresh rain sends the level up once more. And 

 this process is repeated again and again. 



During the N. E. or Winter Monsoon, the rains are heavy and 

 generally continuous. And all the big tanks, streams, ponds, pools, 

 and all low-lying tracts of land get filled up and often overflow. The 

 numerous small rain-water pools that are merely filled up during the 

 Summer Monsoon Season are during this season completely flooded 

 and practically washed out. 



The temperature during the S. W. Monsoon months though 

 slightly lower than in May is still fairly high and the sky is generally 

 cloudy and the weather very sultry, the month of September being 

 the most sultry and trying part of the whole year. But with the 

 advent of the N. E. or the Winter Monsoon, the temperature soon 

 goes down and the weather, though the sky is often cloudy, is quite 

 cool and pleasant. 



The following table gives the details of the temperature, rain- 

 fall and cloud values of the different months of 1919 at Madras : — 



1919 



h £5 



■a a £ 

 -^ o 



§2S 



?Eh o 



° » £ 



c3 id ^ I X CD ^3 



* f-i c \ ,* u a 



ca C S «« S 



03 a) 03 u 05 CD 



bD p,-S ' CO D.-H 



t. C 5_ I J3 C 



3 o 



T3 CD 



s -a 



O u~ 



CD ,-i. 





— 03 



3 c3^3 



25 h ~ 



-a 



CO o 



> *= -5 



! «<» 



1 C CO 



■ C ca 



January 



February 



March 



April 



May 



June 



July 



August 



September 



October 



November 



December 



87°.4 



93-5 



949 



98'3 



108-2 



105-0 



102-2 



1011 



99 



96-2 



90-6 



86-3 



64°.5 



68-4 



66'4 



73-7 



76-5 



70-2 



73-5 



74-0 



733 



731 



70-5 



67-4 



36 

 2S 

 13 

 27 

 33 

 71 

 63 

 66 

 49 

 57 

 61 

 64 



