88 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV 11. 



anatomical characters of the submerged organs and compare them 

 with the submerged leaves of other aquatics, we find that they agree 

 in all the essential points. Nobody will doubt that the submerged, 

 myriophyllum-like leaves of the Cabomba aquatica are true leaves, 

 though they vastly differ from the disc-shaped floating leaves of the same 

 plant. It is easy to adduce other examples of heterophyllous plantsof 

 which it is equally sure that their submerged, finely divided leaves 

 are true leaves, e.g., Potamogeton heterophyllus, rufescens, spathulatus, 

 Ranunculus aquatica, bandotii, hololeucus, species of the genera 

 Helosciadum, Ceratophyllum, (Enanthe, Slum, etc. Tbe submerged 

 organs of Trapa bispinosa agree with all these leaves in their anatomical 

 structure, and exhibit also some common characteristic features in their 

 outer appearance, though, of course, they differ as much from them as 

 their floating leaves do in their external morphological development. 

 An objection might be raised from the unusual position of the submerged 

 leaves of Trapa bispinosa. I think, however, if the anatomical structure 

 is such as to induce us to call a certain organ a true leaf, a mere displace- 

 ment of the organ cannot be decisive in this question. If this were 

 the case, we might as well say that the extra-axillary branches are not 

 branches because they do not arise from the axils. 



