^200 Linnaan Society. 



well, but had not flowered up to the time of Dr. Falconer's leaving 

 India ; and one of these furnished the leaves which were represented 

 in a figure accompanying the paper, together with a small quantity 

 of Asafcetida, diflPering in no respect from the ordinary condition of 

 that substance as it occurs in commerce. The species is found, as 

 it would appear, in the greatest abundance in the Persian provinces 

 of Khorassan and Laar ; and thence extends on the one hand into 

 the plains of Turkestan upon the Oxus, where it seems to have been 

 met with by Sir Alexander Burnes, and on the other stretches across 

 from Beloochistan, through Candahar and other provinces of Affgha- 

 nistan, to the eastern side of the valley of the Indus in Astore. Dr. 

 Falconer has not met with it in Cashmeer. 



Besides the gum-resin, the fruits of the Narthex Asafcetida are also 

 imported into India for medicinal use, and along with them the fruits 

 of another umbelliferous plant which Dr. Falconer found to belong 

 to a true Ferula, and which are sold under the name of Doogoo ; a 

 word evidently connected with the Greek Zuvkos, Of these fruits 

 he gives a description ; and he also mentions another umbelliferous 

 fruit in the collection of Dr. Royle, labelled as " the seed of the 

 Wild Asafcetida plant, collected and brought to England by Sir John 

 MacNeill from Persia," which differs widely from the fruit both of 

 Narthex and Ferula, and belongs to another tribe of the Order. 



November 17. — E. Forster, Esq., V.P., in the Chair. 



Read a portion of Dr. William Buchanan Hamilton's " Commen- 

 tary on the Hortus Malabaricus of Van Rheede." 



December 1. — E. Forster, Esq., V.P., in the Chair. 



Read a paper " On the Structure and Movements of Bacillaria 

 paradoxa, Gmelin." By G. H. K. Thwaites, Esq. Communicated 

 by William Spence, Esq., F.R.S., F.L.S. &c. 



Mr. Thwaites commences his memoir by a description of the spe- 

 cies. The filaments are ribbon- shaped, curved, pale brown with a 

 paler mesial line, and consist each of from 4 or 5 to upwards of 100 

 linear frustules, lying contiguous and parallel to each other. The 

 front view of each frustule exhibits a slight tapering towards the 

 apices, and a minute dentation on the inner edge of the smooth 

 raised lateral margins, the intermediate space being smooth. In a 

 side view, the surface of mutual contact is seen to be linear-lanceolate 

 with the apices rounded ; and the space between the smooth raised 

 lateral margins is marked with transverse raised striae. The length 

 of the frustule, and consequently the width of the filament, varies 

 from ^iy to y|^j of an inch ; and the width of the frustule from 

 ro^oo *^ JcT&o °^ ^^ inch. The frustules are filled (with the ex- 

 ception of a lighter transverse central fascia) with a pale brown en- 

 dochrome ; and the filaments increase in length from multiplication 

 of the frustules by fissiparous division. 



Mr. Thwaites has found this (the original) species of Bacillaria 

 abundantly in ditches at the mouth of the Avon near Bristol, in water 



