LIVERWORTS : MARCHANTIA. 



235 



attachment at the base of the archegonium. Soon, as shown in fig. 267 at 

 the right, the outer portion of tlie spomgonium begins to differentiate into 

 the cells which form the el, iters and those which form spores. These lie in 

 radiating lines side l»y si<le, and form "what is termed the arcIu'sporiiDit. Each 

 fertile cell forms four spores just as in ricci.i. They are thus called the 

 mother cells of the spores, or spore mother cells. 



494. How marohantia multiplies. — New plants of marchantia are formed 

 by the germin.ition of the spores, and growtli of the same to the thallus. 

 The plants may also be multiplied by parts of the old ones breaking away 

 by the action of strong currents of water, and when they lodge in suitable 

 places grow into well-formed plants. As the thallus lives from year to year 

 and continues, to grow and branch the oliler portions die off, and thus sepa- 

 rate plattts may be fjrmcd fmn^ a former single one. 



495. Buds, or gemmae, of marchantia. — But there is another way in which 

 marchantia multiplies itself. If we e\, inline the upper surface of such a 



Fig. 268. 

 Marcliantia plant with cupules and gemmae ; rb.izoids below. 



plant as that shown in fig. 268. we shall see that there are minute cup- 

 shaped or saucer-shaped vessels, and within them minute green bodies. 

 If we examine a few of these minute bodies with the microscope we see that 

 they are flattened, biconvex, and at two opposite points on the margin there 

 is an indentation similar to that which appears at the growing end of 

 the old marchantia thallus. These are the growing points of these little 

 buds. When they free themselves from the cups they come to lie on one 



