OCIMUM 415 
by the insects, which seemed “to be actually invigorated by the apparently 
stimulating effect of their new quarters.” 
The Sergents, in Algeria, experimented both with the castor oil plant (Ricinus 
communis) and with papaya or pawpaw (Carica papaya) on account of the 
reputation that these plants had as deterrents against mosquitoes. A pawpaw 
about 90 cm. high and in good condition was enclosed in a mosquito bar of tulle, 
oblong in form, with its axis directed perpendicularly to the window from which 
the light came. In the end of the bar nearest the window they suspended a 
raisin grape, as food for the mosquitoes, and a little vessel of water. Then at 
the opposite end of the bar they put in four females of Anopheles maculipennis 
and four females of Culex pipiens. They wished to see if the instinct which 
attracts the mosquitoes toward the light and towards an apparent way of escap- 
ing, and on the other hand the need of nourishment and water, would induce the 
mosquitoes to pass the middle portion of the bar which was entirely filled with 
large leaves of the pawpaw. At the end of four minutes one Anopheles and one 
Culex had passed from one end of the bar to the other; at the end of ten minutes 
another Anopheles and two Culex were seen to alight upon the pawpaw leaves 
and they remained there many hours. The mosquito bar was left in place for 
eight days. During this period the mosquitoes moved about freely and rested 
frequently upon the leaves and branches, sometimes for hours. 
An experiment exactly similar was carried on at the same time with Ricinus 
communis, with the same results. When these experiments were concluded at 
the end of eight days one Anopheles and one Culex were found dead in the paw- 
paw mosquito bar, and in the Ricinus bar also one Anopheles and one Culez. 
But in similar cages in another room during the same time with Carica and 
Ricinus plants absent, six Anopheles out of twenty had died, and nine Culex 
out of twenty-eight. The authors concluded that pawpaw and castor oil plants 
are powerless against mosquitoes. 
OCIMUM. 
Another plant which is said to act as a deterrent is a lavender known as Oci- 
mum viride, a perennial which grows from 3 to 6 feet in height and occurs from 
Senegambia southwards to Angola. Mr. A. E. Shipley in the Tropical Agri- 
culturist of February 2, 1903, pp. 555-556, states that Major Burdon, resident 
of the Nupe Province, northern Nigeria, had given him the following account 
of the plant: 
“ A fragment of what turns out to be Ocimum viride was given me in August 
last at Lokoja, Northern Nigeria, by Capt. H. D. Larymore, C. M. G., R. A., 
Resident of the Kabba Province. Capt. Larymore’s notice had been drawn to the 
lant by a native living in a low-lying part of the native town at Lokoja, who had 
told him that the natives suffered very little from the swarms of mosquitoes 
which existed in that part, as they protected themselves from them by the use of 
this plant. 
ne bant. Larymore made inquiries and obtained a few specimens of the plant, 
which grows wild, though not very abundantly, in the neighbourhood of Lokoja. 
These specimens he planted in pots and boxes and kept in and about his house. 
The specimens I saw were about the size of a geranium. 
