1903-1904-] Report of the Microscopical Section. 143 



ovum reaches maturity it consists of a long thin stalk, called 

 the sda, bearing at its end a pear-shaped capsule. This is the 

 fruit of the plant ; and the whole fruit — seta and capsule — 

 constitutes the asexual or spore-bearing generation. When the 

 calyptra is removed the mouth of the capsule is found shut by 

 a lid or opercidum. Eunning through the whole length of the 

 capsule is a solid pillar called the columella, and around the 

 columella, between the inner and outer spore-sacs, is a mass 

 of tissue called the archesporium, in which the spores or seeds 

 of the plant are produced. Between the operculum and the 

 body-wall of the capsule is a row of special cells called the 

 annulus. When the fruit is ripe the cells of the annulus 

 become ruptured and the operculum falls off. Although the 

 lid of the capsule is now off, the way for the dissemination of 

 the spores is not quite clear. . As these spores can be properly 

 scattered only in dry weather, provision is made that they shall 

 be liberated from the capsule only in such weather. This is 

 effected by a double row of teeth, called the peristome, which 

 surround the mouth of the capsule. The cells of the teeth of 

 the peristome are highly hygroscopic, so that in moist weather 

 the teeth close tightly together over the mouth of the capsule 

 and thus prevent the escape of the spores, while in dry weather 

 they open and allow the spores to be disseminated. The spores 

 thus scattered on the ground germinate, and produce a fila- 

 mentous growth called the protonema, from which arise the 

 young plants constituting the sexual generations. 



During the period after the New Year Mr E. A. Staig of 

 the Natural History Department, Glasgow University, gave a 

 series of practical demonstrations in Zoology. His object was 

 to show the gradual development of various types in the 

 animal kingdom and their rise in the scale of existence. In 

 pursuance of this object he chose the following types : — 



Amoeba. — Chosen as a type of the lowest class : animals 

 composed of a jelly-like substance called by Dujardin sarcode. 

 It has now been demonstrated that this sarcode and protoplasm 

 have the same properties — that is, that animal and vegetable 

 protoplasm are identical. The sarcode seems to consist of two 

 layers — an outer, hyaline, and an inner, granular. The first 

 was formerly called ectoplasm and the latter endoplasm, but 



