CITRUS FRUITS IN THE PHILIPPINES. 7 



teresting characteristic has been discovered in several of the 

 citrus fruits that have free stamens in the form of a more or 

 less distinct nucleus in the juice cells; this, so far as the writer 

 knows, has not been previously recorded in a citrus fruit. The 

 fact that the presence of these nuclei is not here referred to 

 in some species with free stamens does not necessarily mean 

 that they are absent, considering that fruits of these particular 

 species have not been examined since the first nuclear cells 

 were discovered. The writer is inclined to believe that these 

 nuclei are correlative to those species having free stamens. 



To the student in the citrus-growing sections of the United 

 States the characterization of the citron, lemon and lime as 

 given herein is no doubt satisfactory, but in the Philippines 

 various forms called "limon" will appear that do not agree with 

 this and it would then be necessary either to make the de- 

 scriptions more general so as to cover the additional forms or to 

 classify these as species or subspecies. If the barely margined 

 petioles, comparatively small leaves, the green, tender growth 

 and the white corolla are insisted upon for the lime, for instance, 

 it is difficult to know where to place the purple-growthed, thorny, 

 wide-winged, purplish-petaled, subglobose limes with wide- 

 winged leaves of the Philippines. They cannot well be placed 

 with the lemons, and still less with the citron, though they of 

 course show strong relationship to each. The citron group 

 of the genus perhaps more than any other shows the need of 

 further study and systematization of the entire genus. 



Attention should be called to the presence in the Philippines 

 of the extremely primitive types of the citron and the lemons; 

 for instance, the fruit illustrated in Bulletin No. 27, Plate XVI 

 (c), and colo-colo, as well as the lombog, referred to C. pseudoli- 

 monum in this paper. 



Of all the plants here discussed, C. micrantha var. microcarpa 

 is botanically furthest removed from the cultivated citrus fruits. 



Each considered as a separate species and constituting per- 

 haps the most complete description of these species published 

 in English, Mr. H. H. Hume's characterization of the orange, 

 sour orange, mandarin, pomelo, citron, lemon, and lime in his 

 "Citrus Fruits and Their Culture," is here reproduced without 

 alteration. Some writers have grouped several of these as sub- 

 species under one great comprehensive species, but, as Mr. Hume 

 aptly says: "What advantage is there in throwing the sour 

 orange, sweet orange, pomelo, kumquat, and a few other dis- 

 tinctly different trees into one conglomerate species * * * 

 and then placing each of the aforementioned plants under this 



