6 PHILIPPINE AGRICULTURAL REVIEW. 



so far as the writer has noted, scarcely enough to warrant the 

 distinction of separate varieties. Both the white and red- 

 fleshed types occur with many gradations, but no studies have 

 been made to note which other correlative characters, if any, 

 are identified with these different forms. The very primitive 

 pomelos (PI. II, c) that are not infrequently seen in cultivation 

 might indicate that this species is indigenous to the Philippines, 

 though so far as the writer knows the tree has never been 

 seen in the virgin forest. Closer observations have been made 

 on the general type represented by the citron, including the 

 lemon and lime, and several distinct forms have been recognized. 



The calamondin, C. mitis Blanco, is well known to be in- 

 digenous, as well as the cabuyao and related plants that have 

 been referred to C. histrix DC. In the first-named species 

 there seem to be no very marked variations. 



C. histrix was described by De Candolle, flowers and fruits 

 excepted, from a plant growing in Montpellier, being recognized 

 principally by its long broad-winged petioles and free stamens. 

 The writer has not had the opportunity to see the original 

 Description of C. histiix or examine the type specimen, but 

 Swingle refers to it in Jour, of Agri. Research, Vol. I, No. 1, 

 page 10, 1913, as having broadly winged petioles, often larger 

 than the blades, the wings being more gradually narrowed 

 toward the base and usually more abruptly truncate at the tip 

 than C. ichangcnsis Swingle, making then somewhat triangular 

 in outline. 



Within these broad limitations a number of otherwise re- 

 markably distinct forms may be recognized some of which were 

 illustrated in a previous publication, Bureau of Agriculture 

 Bulletin No. 27, Citriculture in the Philippines, 1913, and re- 

 ferred to C. histrix with the statement that "some of these 

 forms unquestionably will be recognized as subspecies on closer 

 study, or possibly as separate species." Since then several 

 plants of this type in the citrus collection assembled at Lamao 

 by the Bureau of Agriculture have bloomed and fruited, afford- 

 ing an opportunity for fuller observations, and these have been 

 further complemented during a trip to Bohol and Cebu in May, 

 1914, and by the fruits forwarded by Mr. E. F. Southwick. 



However, assuming that C. histrix (or some of its subspecies) 

 is the C. histrix of De Candolle, there still remain, on one 

 hand the limao, and on the other the biasong, balincolong, sa- 

 muyao, samuyao-sa-amoo, as widely different from each other 

 and the cabuyao and its subspecies as for instance the orange, 

 and pomelo, or the mandarin and the calamondin. A very in- 



