SPH^ROSTOMA OVALE FROM PETTYCUR, FIFESHIRE. 7 



the tangential section shown in fig. 4 we see two lobes which in the specimen can 

 be shown to be distinct. In an obliquely transverse section of the micropyle (fig. 3), 

 which passes through the "frill" on one side, the lobe cut through is seen to be 

 distinct from its neighbours, and its outline corresponds at its base with one of the 

 small crests within the micropyle. Thus it can be stated that the micropyle at its 

 extreme apex was surrounded by eight lobes of the canopy, each crowned by an outer 



Text-fig. 3, a. — A radial section of that part of the inner integument which lies immediately above the plane of text-fig. 2, 6, 



as plotted on text- fig. 1. 

 aq. = ? aqueous tissue of the canopy ; s. = sclerotic sheath; v.l). x — the extreme apex of one of the eight 

 vascular bundles that pass up the inner integument. 



b and c. — Figures to show transverse sections of young and old epidermal secretory cells, m.c. 



& = a young intact cell with papilla. Also two hypodermal fibres from the sclerotic sheath, s. 

 c=an epidermal secretory cell showing liberation of hemispherical cap. 



and an inner epidermal crest, of which the outer was the larger. Lower down the 

 micropyle, the epidermis contracts into a uniform layer over the eight sides of the 

 octagonal sinus. Just as the sinus widens out below the micropyle, the epidermis again 

 becomes papillate and secretory. The papillae are numerous and basiscopic. Below 

 the surface formed by the secretory tissue lies a mass of parenchyma, behind which 

 terminates the tracheal system (text-fig. 3, a, v.b.^). 



The epidermis on a level with the pollen chamber again becomes smooth and 

 apparently non-secretory. Below its surface we find the large rounded cells accom- 

 panying the vascular bundles throughout their entire length (text-fig. 3, aq.). They 



