220 On Sexual Changes m the Inflorescence of Zea Mays. 



adduced of a bisexual species undergoing sexual metamor- 

 phoses similar to those above described in the unisexual 

 maize. Moreover, supposing that the sexual characters of 

 hermaphrodite plants had exhibited masquerading ten- 

 dencies similar to those of unisexual plants, it is at once 

 evident, that, upon any theory of special creation, the cause 

 of such changes in either case is equally unintelligible. On 

 the other hand, if, with Mr Darwin, we believe that species 

 are the modified descendants of previously existing species, 

 these phenomena are no longer enigmatical, but clearly the 

 results of definite and well-known laws. I need only refer 

 to Mr Darwin's interesting papers on the distinct sexual 

 forms of the dimorphic species of Primulas and Linums, 

 "Jour. Linn. Soc.,'' vol. vi. p. 77, and vol. vii. p. 69, by 

 way of illustrating, as has been remarked, the possibility 

 of a plant becoming dioicous by slow degrees." Now, if 

 we reflect on this dimorphism of the Primulas and Linums, 

 those differences in the variability of the unisexual, re- 

 latively to the bisexual flowers, are, I believe, readily expli- 

 cable on the supposition that the latter — i.e., the herma- 

 phrodite structure, as Professor A. Gray has maintained — 

 vide " Sill. Amer. Jour./' vol. xxxiv. — " is the normal or 

 primary condition of flowers." In fine, then, in accordance 

 with the theory of modification vv^ith descent, I, inferentially 

 guided by that principle of reversion to type so much 

 insisted upon by those opposed to derivative hypotheses, 

 look confidently at such sexual changes as those above 

 described, as retrogressive tracings of the graduated modi- 

 fications by which an original hermaphrodite progenitor 

 gave rise to a monoicous offspring. 



Neio Besearches on Hyhridity in Plants. By M. Ch. 

 Naudin. Translated from the Annales des Sciences 

 Naturelles, by George May Lowe, Esq.* 



(1.) On the Sterility and Fecundity of Hybrids. 

 A century ago, Koelreuter demonstrated by proofs which 

 no other observer has ever surpassed in exactitude, and which 



* Read before tlie Botanical Society of Edinburgh January 14, and March 

 10, 1864. 



