20 MADRONO [Vol. 1, 



The drawings represent in both cases sections of material im- 

 bedded in paraffin and cut 15 microns thick. (Fig. 7a.) 



Fig 6. Teratological flower of T. sessile, var. giganteum H. & 

 A. Three ovules can be seen, at the head of the arrow, borne 

 along the margin of a modified petal. 



In the upper drawing is shown a portion of the cross-section of 

 a normally produced ovary of Trillium, to show the appearance and 

 structure of the ovules. (Fig. 7b.) 



The lower drawing represents a cross-section of one of the 

 modified petals found in the abnormal flower shown in the photo- 

 graph and described above. This lower drawing is partially recon- 

 struction, since no two ovules on opposite edges of the same modi- 

 fied petal gave exactly similar views in any one section. In both 

 drawings only cell outlines are shown, since the tissue of the ab- 

 normal flower was not prepared for sectioning until some days 

 after its collection, and the contents of the cells had, to some extent, 

 degenerated. 



As shown in these drawings, the similarity between the struc- 

 tures borne normally within the ovary attached to the placenta and 

 those present along the margins of perianth segments is striking. 

 There seems to be no room for doubt that we are dealing here with 

 a case of pistillody in which the perianth segments of the flower 

 are concerned; that is to say, three segments of the six-parted 

 perianth bear ovules, and thus function in a sense as pistils or bet- 

 ter as carpels. It is evident that if these three modified petals were 

 first folded to bring their ovule-bearing margins together and thru all 

 three united along these double edges, a three-celled or three-car- 

 pelled structure would be produced that would correspond exactly to 



