24 



PHYSIOLOGY. 



bathed with the water. This is known as MarcJuinlia poJy- 

 nwrpha. If we examine the under surface of the niarcliantia 

 we see numerous hair-like processes which attach the plant to 

 the soil. Under the microscope we see that some of these are 

 similar to the root hairs of the seedlings which we have been 

 studying;, and they serve the purpose of absorption. Since, how- 

 ever, there are no roots on the marchantia plant, these hairdike 





Fig. ,11. 

 Marchantia plant witlt cupules and gemmx ; rhiziiids ttelow. 



outgrowths are usually termed here rliizoids. In marchantia they 

 are of two kinds, one kind tlie simple ones with smootli walls, 

 and the other kind in which the inner surfaces of the walls are 

 roughened l)y processes wliich extend inward in the form of irret;- 

 ular tooth-like points, liesidcs tlie hairs on tlie under side of 

 the thallus we note especially near the growini,' end that there are 

 two rows of leaf-like scales, those at the end of tlie thallus curv- 

 ing up over tlie .throwing end, thus serxing to protect the delicate 

 tissues at the growing point. 



