DR. BEALE^ ON THE TISSUES. 261 



centre of a mass of germinal matter, and this might be mis- 

 taken for a nucleolus, but it is not coloured by carmine; and 

 by carefully examining several masses in different stages of 

 groAvth, its true nature can be made out. In other cases the 

 fatty matter is deposited on one side of the germinal matter, 

 which gradually becomes pushed to the opposite part. In 

 both cases the relation of the germinal matter to the in- 

 vesting membrane and the secondary deposits is precisely 

 the same. 



Sometimes particles in all parts of the germinal matter 

 rapidly grow, pass through their stages of existence, and 

 become resolved into a substance allied to that which is ordi- 

 narily applied to the thickening of the outer membrane. In 

 this case the germinal matter will be found partly just within 

 the membrane, and partly am^ongst the insoluble particles in 

 the interior. In the large, starch-holding cells of the potato 

 the living germinal matter is seen to be in contact with the 

 inner surface of the capsule, while the starch-granules accu- 

 mulate, for the most part, in the centre. 



There is no difficulty in finding starch-granules in every 

 stage of formation ; and careful examination will lead the 

 observer to the opinion that the starchy material is deposited 

 in successive layers, so that the inmost are the first, and the 

 outermost the last layers which have been formed, and the 

 deposition has taken place more rapidly at one part than at 

 another, as shown by the different thickness of the layers at 

 different parts of their circumference. 



The following very interesting point will also be observed 

 by careful examination of sections of potato : — Insoluble 

 matter has been deposited in successive layers on the inner 

 surface of some of the large capsules, producing a laminated 

 appearance exactly resembling that of a starch -granule, but 

 spread out, as it were, over an extended surface. It is also 

 important to observe that, at short intervals, there are open- 

 ings in these transparent lamellse through which nutrient 

 material passed into the interior of the capsule. These are 

 more correctly described as spaces, or channels, which 

 probably are closed on their outer surface by the thin mem- 

 brane of the original eell-wall. Here the deposition of 

 insoluble matter has never taken place, and through the 

 spaces, currents of fluid pass to the interior, and continue as 

 long as any living matter exists within in an active state. 

 The mode of deposition of this insoluble matter can be very 

 satisfactorily watched in these capsules."^ In many other 



* These insoluble lamellse are not starch, althongli they refract and polarize 

 like this substance. The peculiar cells contain very little starch, and there 



