Beer.- — On the Development of the Spores of Ricci a g lane a. 291 
Fig. 31. Second division of the mother-cells and young tetrad. Secondary and tertiary thicken- 
ing layers of the mother-cell wall still surround the periphery of the cells. 
Fig. 32. First division of the egg-cell. 
Fig. 33. Sporangium containing spores with two-layered coats. Note mucilage between the 
spore-tetrads. 
Fig. 34. Spore at about middle period of its development treated with iodine solution to show- 
distribution of starch. 
Fig. 35- Section of spore showing layers of its wall. Darkly coloured layer is particularly 
noticeable. 
Fig. 36. Section of spores to show the new lamellae which are to be added to the thickness of 
the second spore-wall plasmolysed away from that wall together with the protoplast to which they 
are firmly fixed. These lamellae gave cellulose-pectose reactions. 
