4-iO APOSTASIS. 



pistil, either in association with a leafy condition of 

 the pappus or without any such change. 



Elongation of the thalamus, placenta, &c. In some plants, 

 as in Magnolia or Myosurus, the thalamus becomes 

 much elongated, and bears the carpels disposed spirally 

 around it. A similar lengthening occurs in malformed 

 flowers, usually in association with a similar change in 

 the lower or outer part of the flower, by virtue of 

 which the whorls become separated from each other 

 (Apostasis). Elongation and protrusion of the placenta 

 have been already alluded to at p. 119, and also at 

 p. 125. In some of these cases the elongated placenta 

 has taken the form of a leaf-bearing shoot.' 



Apostasis. Engelmann made use of this term to ex- 

 press the separation of parts one from another by the 

 unusual elongation of the internodes." He drew a 

 distinction between the separation of individual organs 

 one from the other, and the corresponding displace- 

 ment of whorls. The subject has already been, to a 

 considerable degree, treated of in these pages under 

 the head of dialysis, displacement, and prolification, 

 and but little need here be added. With reference to 

 the distance between one whorl and another, it will be 

 remembered that, although in the majority of cases the 

 floral whorls are packed closely together^ yet in other 

 instances the floral axis becomes elongated, and thus 

 separates the whorls one from another, by structures 

 such as the gynophores, androphores, &c., of Passi- 

 floreoB, Caryophylleai, CapparideWj &c. &c. 



A similar elongation of the thalamus, bringing about 

 the separation of the floral whorls, or of their con- 

 stituent parts, is very commonly met with in association 

 with median prolification. Where the individual floral 

 elements are thus thrown out of their usual verticillate 

 arrangement, they naturally assume a spiral disposition, 



' For further details refer to the chapter on Displacements, p. 86. 

 - * De Antholysi,' p. 42, 19. 



