angular portion, the secondary lobe", in the distal axil of 

 primary lobe. 



Type (b). Bursa bursa-pastoris rhomboidea has the le* 

 divided to the mid-rib as in B. bp. heteris. The lateral lobes h 

 an incision on the distal margin setting off the secondary ] 

 from an unelongated primary lobe. There is usually a co 

 spending incision on the proximal margin of the primary 1 

 In the best developed specimens these incisions set off a si 

 terminal portion of each lateral lobe ; which is rather blun 

 "angular at the apex, being generally of rhomboidal form. I 

 perfectly developed specimens have the incisions very shallow 

 nearly wanting, but retain the characteristic deep sinuses extenc 

 to the mid-rib. 



Type (c). Bursa bursa-pastoris tenuis differs from both 

 and (b) in that the sinuses do not usually reach the mid 

 The terminal lobe is not separated from the nearest lateral k 

 by deep, clean-cut sinuses, these more distal sinuses being r 

 tively shallow, so that one can with but scant propriety sp 

 of the terminal lobe as a definite morphological structure. All 

 lateral lobes tend to be elongated and sharp, and no incis 

 are present to set off a secondary lobe, though in particuL 

 vigorous specimens there may be a slight expansion of leaf-ti{ 

 in the region occupied by the secondary lobe in B. bp. kei 

 and B. bp. rhomboidea. 



Type (d). Bursa bursa-pastoris simplex, like B. bp. tenui 

 scarcely ever divided nearly to the mid-rib, and the lateral k 

 are mostly obtuse, sometimes more or less acute, but never 1 

 and attenuated. No secondary lobing appears except occasion 

 a slight denticulation on the margins. 



These descriptions refer to the characters of the clim 

 leaves in well-grown specimens, as all of these types have ji 

 nile leaves entirely unlobed and indistinguishable from the ji 

 nile leaves of the other forms, and the late rosette-leaves 

 stem-leaves likewise generally lack distinctive features. Un 

 poor cultural conditions plants frequently complete their developm< 

 flower, and ripen their seeds, without exhibiting any but th 

 juvenile and senescent characters. The complete procession 

 leaf-forms in typical specimens of the four described biotypes 

 shown in the plates I IV. 



