1902] A MORPHOLOGICAL STUDY OF ASCLEPIADACEAE 397 



writers have considered the head stigmatic. Corry (5), limiting 

 the term stigma to that portion fitted for the reception of the 

 pollen, naturally regards the head stylar. One is led to conclude 

 from his statements that he believed the tips of the carpels were 

 abaxially reflexed to the functional stigma, seeing an argument 

 for it in cases of the reflexion of the fibrovascular bundle. The 

 conductive tissue, however, does not follow the path which a 

 definite location in a recurv^ed leaf would give it; and if it is not 

 definitely placed in the carpel, its outcrop, the stigma, is not 

 more definitely located. Those who believed the head to be of 

 stigmatic origin thought the functional stigma to be under the 

 corpusculum. The question here is a phylogenetic one. Has 

 the stigma always been where it now is, the head developing 

 above it later ; or, teleologically speaking, has the stigma moved 

 to adapt itself to the modifications of the floral organs? The 

 papillose epidermis of the funnel-shaped depression in the top of 

 the head, the suggestion of conductive tissue in appearance of 

 the cells beneath this epidermis, the absence of a downward 

 curve in the tips of the bundles, and the continuation of the 

 conductive tissue above the functional stigma, all indicate that 

 the homologue of the stigma in other plants is the funnel. We 

 may then regard the head as an abaxial thickening of the style 

 immediately beneath the stigma. We would then have later the 

 formation of a new stigfma beneath the head, and the cessation 

 of functional activity in the one at the top. The strongest argu- 

 ment in favor of Corry's theory, however, and one not mentioned 



I by him, is found in the Apocynaceae. Here one finds stigmas 



on the equator of a fusiform head, a stage between the terminal 

 stigma of the Gentianaceae and the subcapital one of the 



\ Asclepiadaceae. 



\ Incidentally, many of the stages in the formation of the 



caudicules and corpuscula were observed and Corry*s account 

 (5) confirmed. 



The conductive tissue lines the placenta and the canal that 

 forms the continuation upwards of the cavity of the ovary. Just 

 beneath the head it spreads out as a disk or funnel, reaching the 

 surface in a circle under the head (/^. 28), The stigma there- 



