364 THE UNIVERSE. 



corresponds to the importance of the task confided to it. 

 Before the invention of the microscope men were far from 

 thinking how curious it is. It was considered to be only a 

 formless dust; the valuable instrument has revealed the 

 fact that, on the contrary, it possesses a distinctly defined 

 configuration, which varies very much both in regard to its 

 general form and the ornamentation of its surface. This 

 diversity is even great enough to allow some botanists to 

 make it the basis of their classification of plants. 1 



It is generally the globular form that predominates, but 

 there are also grains which are ovoid ; some triangular ones 

 are known, and others resemble gourds or pyramids. Their 

 surface is sometimes smooth, sometimes roughened with 

 papillae, or defended by an armature of spines. But micros- 

 copy is not limited to this ; it shows us that each of these 

 pollen grains is really a charming little utricle with a 

 double envelope, inclosing a fluid in which sometimes swim 

 myriads of animalcules. 2 This fluid escapes by irregular 

 openings which are caused by the bursting of the pollen, or 



1 Although they possessed very imperfect means of observation, our predeces- 

 sors were nevertheless struck by the variety of the pollen grains. Adanson, who 

 pushed his mania for classifications so far as to produce sixty-five, and who based 

 them on the first things which struck him, even the smell and taste of plants, did 

 not omit to form a classification based on the configuration of the pollen. 

 Adanson, Families des Plantes. Paris, 1763. Preface, p 286. 



2 The microscope was very little used by the botanists of last century, and we 

 must come to our own age before we find the pollen perfectly described. Guille- 

 min attentively studied the infinite variety of its forms and surface. The fluid 

 contained in each little pollen-vesicle was particularly studied by Messrs. Mirbel, 

 Brongniart, and Seringe, who all consider the numerous corpuscles which move 

 about in the midst of it as so many microscopic animalcules. The German bota- 

 nists, such as Schacht and others, designate them under the name of antherozoa, 

 in order to leave no doubt on the subject. 



