2 24 WINTERING HABITS [ch. 



consequence of want of food, and at the cost of the reserve 

 material in the parent tuber. At the same date no second 

 generation of tubers had been developed by the normal control 

 plants among Gluck's cultures. 



Myrio-phyllum verticillatum illustrates yet another character 

 of winter-buds namely the close relation which they some- 

 times bear to the flowers and inflorescences. Gliick^ records 

 that in the case of an infructescence of this plant which had 

 become submerged, the continued development of the axis 

 produced an ordinary turion at the apex. The connexion 

 between flowering and vegetative reproduction is also well shown 

 in certain other hydrophytes, and notably in the Alismaceae. 



"A' 



Fig. 147. Echinodorus ranunculoides, (L.) Engelm. var. repens forma terrestris. 

 Habit drawing to show transitions between inflorescences and entirely vegetative 

 rosettes. (Reduced.) [After Gliick, H. (1905), Wasser- und Sumpfgewachse, Bd. i, 



PI. II, fig. 16.] 



Fig. 147 shows transitions between inflorescences and vegeta- 

 tive ofi^shoots in the case of Echinodorus ranunculoides. Caldesia 

 parnassijolia is an even more striking example, for here the 

 inflorescences may be transformed into axes bearing turions 

 (Fig. 148). Fig. 149 ^ shows part of an inflorescence of this 

 plant, in which whorls of turions replace the flowers, while 

 Fig. 149-5 represents the germination of one of these turions. 

 In Caldesia^ and in other Alismaceae, the transformation of the 

 inflorescences into vegetative shoots goes on step by step with 

 the increase in depth of the water. In this connexion it may be 



1 Gluck, H. (1906). 



