420 NINETEENTH CENTURY. FT. in, 



is at the opposite end to the hilum, or place where the seed 

 breaks off from the funicle. In the almond-seed, on the 

 contrary, the embryo is turned upside down, or inverted; 

 the micropyle is close to the hilum, while the funicle passes 

 right round to the other end, carrying the nourishment, as 

 before, opposite to the tip of the plumule. Lastly, the 

 embryo in the hemp-seed is neither upright nor inverted, 

 but curled round so that the micropyle and the funicle are 

 both close together ; and yet the rule is still observed, that 

 the root should point to the micropyle and the plumule to 

 the funicle. The study of the structure and position of the 

 ovule are now of great use in classifying plants. 



Protoplasm Hugo von Mohl, 1805-1872. The 

 microscope had now revealed the history of some of the 

 most delicate structures of plants, but one question remained 

 unanswered, namely, What is the living active matter which 

 forms the cells, the tissues, and the fibres ? The answer to 

 this question was found in the year 1853 by the German 

 botanist, Hugo von Mohl, when he showed that the young 

 cells of plants are filled with a thick semi-fluid substance 

 full of innumerable white granules and that, as the cell 

 expands, these granules flow in streams from the centre to 

 the circumference of the cell in never-ceasing activity. 



We find this semi-fluid living matter equally in the 

 embryo-sac of the young ovule and in all the cells of a young 

 plant ; and from it is formed that inert or dead matter which 

 composes the cell wall ; and, because it is the simplest form 

 of vitality known to us, and out of it all the life of the plant 

 springs, Von Mohl called it Protoplasm, or \^& first formative 

 material. 



Chemists have now shown that this living active pro- 

 toplasm is composed chiefly of the four elements hydrogen, 

 oxygen, nitrogen, and carbon, and plants have the power of 



