230 GENUS PASSERINA. 



As regards the commercial side of the proposition little can 

 be said here. In 1920 the cost in South Africa of milk and sugar 

 to produce one case of 48 tins of condensed milk was about 15/-, 

 against 6 dollars 38 cents in the United States. Even allowing 

 for variations in exchange it will become evident that South Africa 

 has a huge new industry open to it. 



Both the writers have had considerable experience with con- 

 densed milk. It is not too much to say that condensed milk manu- 

 factured recently in South Africa can compete as regards quality 

 in the world's markets with the best imported brands. 



It is only possible here to mention products such as milk 

 powder, casein and various other by-products, the manufacture of 

 which would naturally grow up with the main industry. 



Finally the tremendous effect such an industry would have 

 on the pastural development of South Africa must not be over- 

 looked. At the present time owing to long distances from town 

 the only way for farmers to dispose of milk is to separate and sell 

 butter-fat. This entails labour and little profit, and little induce- 

 ment is given to the farmer to increase production. Establish- 

 ment of condensed milk factories which can afford to pay the 

 farmer a remunerative price and receive his output at all times 

 must make for increased and more profitable dairy farming in the 

 Union. 



THE GENUS PASSERINA AND ITS DISTRIBUTION IN 

 SOUTH AFRICA. 



BY 



D. Thoday, M.A., 

 Professor of Botany, University of ('aye Town. 



Read Jidy 15, 1921. 



Abstract . 



In the course of investigations following upon the observation 

 communicated at Bulawayo last year, that the leaves of Passerina 

 fili for mis and of some other plants with ericoid leaves close the 

 leaf -grooves in time of drought, different forms of Passerina have 

 been met with which could not be satisfactorily identified either 

 by means of the "Flora capensis" or by comparison with herbarium 

 specimens recently identified at Kew. A careful perusal revealed 

 more than one instance of inconsistency, and it has appeared 

 necessary to attack the classification of the genus dc novo. Through 

 the courtesy of those in charge of the Herbaria of South Africa 

 all the available specimens have been examined and compared. 

 Thirteen forms have been recognised, all of which can be dis- 

 tinguished from one another with certainty, the available material 

 providing no intermediates. One of these forms, found in marshy 



