1888.] Sporophyte of Splachnum luteum. 149 



of the apophysis and certain of the organs of the sporophyte with 

 which we are now concerned. 



A transverse section through the vaginula, including the foot of the 

 sporophyte, shows that the tissues of the oophyte in this part contain 

 a considerable quantity of organic substance, and this is seen to be 

 more particularly the case in the layers of cells next to the foot. The 

 foot itself is seen to consist of a cylindrical mass of parenchyma, with 

 an external layer of epidermal cells of a somewhat columnar form, 

 which contain a considerable quantity of protoplasm, and contain 

 large distinct nuclei. The protoplasm of these cells is found to be 

 aggregated towards the peripheral surface, the nucleus being usually 

 found in the mass of protoplasm next to the outer wall of the cell. 

 The large vacuoles of these cells are traversed by fine protoplasmic 

 filaments. These cells, as well as those of the cortical layer beneath 

 the epidermis, contain a number of very small protoplasmic bodies, 

 which are found congregated in large numbers round the nuclei of 

 the cells, there being also some in other parts of the cell, both in the 

 peripheral layer and in the fine protoplasmic filaments traversing the 

 vacuole. In the epidermal cells these bodies are particularly 

 numerous, and are found principally in the aggregated mass of proto- 

 plasm on the outer side of the cells. These bodies may, I think, be 

 safely regarded as leucoplastids. From their number and position, I 

 am inclined to believe that they are concerned in absorbing substances 

 from the tissue of the oophyte for the nourishment of the sporophyte. 

 No starch has been found in the foot. 



In the centre of the foot there is a definite central strand consisting 

 of two kinds of tissue, an outer phloem-like layer of cells containing 

 protoplasm by means of which it is probable that organic substance 

 travels, and an inner strand of very thin- walled cells without any 

 protoplasmic contents* which conducts the water up the seta. In the 

 foot the protoplasm of the phloem-like cells is aggregated in each 

 cell towards the periphery as in the epidermal cells, but there are no 

 plastids present. The strand of thin-walled empty cellsf I have 

 been able to prove in other species of Splachnum conveys the water 

 absorbed by the foot up the seta into the tissues of the apophysis. 



The seta has a distinct epidermis beneath which there is a layer of 

 sclerotic supporting tissue, and then a layer of parenchyma, the two 

 together forming the cortex. In the centre is the central strand, 

 which in the lower end of the seta has almost the same structure as 

 that described for the central strand of the foot, from which it is 

 distinguished by being larger and less distinctly delimited from the 



* Cf. Vaizey, loc. cit. The terms leptophloem and leptoxylem have been used 

 to indicate these tissues. For fuller explanation, see paper referred to. 



f Vaizey : " Note on the Transpiration of the Sporophore of the Musci." ' Annals 

 of Botany,' vol. 1. 



