the Development of the Theca, and on the Sexes of Mosses. 503 



theciurn of an anther, that in Jungermannia multifida its tissue is fibrous. 

 The remarkable manner of the development of sporules and pollen is a most 

 convincing analogy ; they are developed in unions of fours in the cavities of 

 simple cellules; in fact, they are secretions in the cellules which occupy the 

 interior of the theca or anther, and are the only instances on record within 

 ray knowledge, of organized secretions in the cavities of simple cellules. 

 Although the tetrahedral union of both sporules and pollen is almost always 

 dissolved at an early period, yet in some instances, as in CEdipodium and 

 Erica Tetralix, it remains at maturity. Again, neither sporules nor pollen 

 ever have the slightest apparent organic connexion with the parent plant, — 

 a most remarkable coincidence, and a fact which has never been insisted on 

 as a distinguishing character between sporules and seeds*. 



Then to apply, as it were, the precision of a chemical test, if sulphuric acid 

 be applied to the sporules, the same phenomena occur as when it is applied to 

 pollen. The effects of this test vary according to the nature of the contents 

 of the sporule and the manner of its application, which must be carefully 

 regulated to ensure a satisfactory result. If the sporules of Gymnostomum 

 truncatulum., the contents of which are almost entirely fluid (Tab. XXXV. 

 fig. 1 .), be submitted to its action, they will burst, and a portion of the fluid 

 will be discharged in various-sized globules (Tab. XXXV. fig. 2.). No pre- 

 caution that I know of will ensure a different result in this species ; but if 

 sporules whose contents are chiefly granular, such as those of Leskea sericea, 

 Tortula ruralis var. Icevipila, or Tortula rigida, be submitted to the action of 

 the acid, which must be added to the water very cautiously and gradually, 



* I am aware that the sporules of Anthoceros punctatus are described by Hooker as being attached 

 by a stalk to a central columella ; and also, that Dr. Lindley has described the sporules of Andrcea as 

 being attached to the columella. Dr. Lindley also describes from Brongniart and Bauer the sporules 

 of Salvinia and Azolla as stalked. In the case of Andrcea he is certainly incorrect ; and it is quite 

 evident, from the account he has given of the latter plants, that their structure is involved in much 

 obscurity. If it should be decided that these bodies are really attached by a stalk to a placenta, I 

 should be inclined to suspect that they were not mere sporules, for it seems improbable that bodies, 

 developed as sporules are in the cavities of cellules, should be attached by a stalk. May not what is 

 called the theca be an involucrum, and the supposed sporules, each of which in Anthoceros is described 

 as being compounded of three or four smaller bodies, be thecse, each containing either a single union 

 of four sporules, like Lycopodium selaginoides , or only one sporule, the rest being abortive, like Pilu- 

 laria } 



