Mr J. Scott on the Sexuality of the Higher Cryptogams. 197 



be argued that as tlie S. Danielsiana—S. 31. compacta—is the 

 more incipient form of the two experimented upon, it may 

 yet have a tendency to produce, by a truly parthenogenetio 

 'process, a varying offspring from its spores. To this I can 

 answer only as follows, but the answer, I think is satisfac- 

 tory. First^ "When the macrospores oi the S.. Danielsiana 

 and S. Martensii are sown alone, neither — and I speak from 

 an extensive series of experiments — loill produce a single 

 plant ; clearly demonstrating, as I think, a sexual reproduc- 

 tion dependent on the mutual action of both kinds of spores. 

 That consequently parthenogenesis, in so far as my experi- 

 ence goes, does not occur in either of these forms ; nor indeed 

 in any of the species of Selaginella lohich I have tried, if 

 sufficient care he taken to exclude the mic7'ospores. Again, 

 secondly. When the microspores and macrospores of the S. 

 Danielsiana and Martensii are each purely commixed and re- 

 spectively sown in distinct pots, they reproduce themselves 

 perfectly, as I have in several instances proved by experi- 

 ments. That the Society may be enabled to judge as to the 

 truth of this statement, I have placed upon the table seed- 

 ling plants of both forms, all of which betray at once their 

 respective parents. Conjoining, then, the latter with the 

 foregoing evidence, i.e,, the non-development of the macro- 

 spores when sown alone, and the facility with which both 

 forms reproduce themselves when the tivo hinds of spores 

 are mixed ; and comparing them with the previously given 

 history of the presumed hybrid, we are thus, as I am inclined 

 to think, afforded, firstly, most conclusive evidence of the 

 existence of true sexual organs in these plants ; and, secondly, 

 indubitable proofs of the mixed origin of the seedling plant. 



Let us now see in how far this view of the mixed origin 

 of the seedling plant is supported by an individual and 

 comparative examination of the morphological character- 

 istics of the latter and its parent forms. First, for the in- 

 dividual characteristics : — 



1. Selaginella Martensii.— Spike sessile, linear, somewhat 

 attenuated, from 8 to 10 millimetres long. Bracteas ovate, 

 acuminate, denticulate. Microsporangia ovate, subtrun- 

 cate, tumid, f of a millimetre. Microspores reddish-orange, 

 of a millimetre, somewhat wrinkled and granulated. 



NEW SERIES. VOL. XTX. NO. II. APRIL 1864. 2 C 



