ON THE HIGHER CRYPTOGAMOUS PLANTS. Ill 



Finally, Hofmeister, in his notice of this essay in the ' Flora*,' declares that 

 the development of the so-called ' embryo' or first frond commences, not by 

 the subdivision of the globular cell or ' embryo-sac,' but by the development 

 of a free cell or 'embryo vesicle' in this, like what occurs in the embryo-sac 

 of the Phanerogam ia ; and he asserts that this is the first stage of develop- 

 ment from the globular cell in all the vascular Cryptogams, including that 

 found in the pistillidia of the Mosses. 



Equiselacece. — The first discovery of the analogy between the developments 

 from the spore in germination, in the Ferns and Equisetaceae, is due to M. G. 

 Thuretf, who saw the spores of the latter produce a cellular pro-embryo 

 somewhat like that of the Ferns, and in this were developed antheridia of 

 analogous structure, emitting cellules containing many spiral filaments. 



This announcement was confirmed by M. MildeJ, whose observations 

 extended over some months, during which time no ' ovule ' was produced, 

 but he saw what appeared to be the rudiment of one. Dr. Mettenius§ states 

 that he has met with decaying ' ovules ' precisely like those of the Ferns, 

 upon the pro-embryo of an Equisetum, and thus the evidence is completed, 

 so far as the occurrence of t^he two kinds of organs is concerned. 



Lycopodiacece. — The fructification of this family consists, as is well known, 

 of spikes clothed with fruit-leaves, bearing on their inner faces sporangia 

 containing spores. These spores are of two kinds. One sort occur in large 

 numbers in their sporangium, and are very small ; the others are much 

 larger, and only four are met with in a sporangium. Spring ||, who has devoted 

 great attention to the general characters of the Lycopodiaceae, has given 

 especial names to the two kinds of sporangia ; those with the four large 

 spores he calls oophoridia, those with the small spores antheridia ; yet he 

 did not mean to attribute a sexual antithesis, merely a morphological one, 

 as he expressly states. 



The general impression however with regard to the import of the two 

 kinds of spores has long been, that the large spores alone are capable of pro- 

 ducing new plants, and five years ago Dr. C. Miiller published an elaborate 

 account of the development of the Lycopodiaceae^, in which the germination 

 of the large spores was described at length. The following are the essential 

 results of his investigations. 



The large spores are more or less globular bodies^ usually flattened on 

 the surfaces by which they are in contact in the oophoridium ; thus, while the 

 outer side has a spherical surface, the inner side has three or four triangular 

 surfaces, as in L. selagmoides, and L. denticulatum. They possess two coats, 

 the outer very thick and composed of numerous cells, the cavities of which 

 are almost completely filled up by deposits of secondary layers. This outer 

 coat exhibits various forms of raised markings on its outer surface, and in 

 some cases these seem to form a distinct layer, a kind of cuticle, capable of 

 being separated from the subjacent cells. The inner coat of the spore is 

 usually perfectly structureless, and not very firmly attached to the outer coat. 

 In L. gracillinmm Dr. Miiller observed below the outer coat a structure com- 

 posed of a layer of rather large parenchymatous cells, wiiich could be easily 

 isolated ; and as there was no structureless membrane within this, he regarded 

 tlie layer as the proper inner coat. This observation is important in relation 

 to the discrepancies between Dr. Miiller's statements and those of Mettenius, 



* 1850, p. 700. t Ann. des So. Nat. 1849, vol. xi. 5. % Linnsa, 1850. 



§ Beitriige zur Botanik, 1850, p. 22. H Flor. Brasiliensis, 106-108. 



f Botanische Zeitung, July 31, 1846, et seq. num. Ann. of Nat. History, vol. xix. 1847. 



