364 ANIMAL NATURE OF DIATOMEJ3. 



a later period transversely, forming four lobes, which at 

 a later period divide into minor portions. Hence Kiitzing 

 infers that this substance corresponds with the gonimic 

 matter of Conferva? and Alga? in general. And he ad- 

 duces, as a principal argument, that by means of alcohol 

 he can extract from the Diatomeae a colouring matter 

 similar to chlorophyll. 



There exist, besides, among this substance, minute, 

 colourless, and transparent spherical globules, varying, in 

 the same species, in number, size, and disposition, at 

 different stages, and we may add, according to various 

 conditions, even under the eye of the observer. Kiitzing 

 describes them as oil globules, because he saw them run 

 one into another, as well on the inside as the outside of 

 the shield. And he adds that these oil globules, in 

 appearance and position, exactly resemble grains of 

 starch in other Algse, for which they seem to be sub- 

 stitutes, as happens in the cotyledons of CruciferaB. 

 The oil globules of Kiitzing are regarded by Ehrenberg 

 as glands representing the male sex, and the supposed 

 gonimic substance he thinks belongs entirely to the 

 ovaries. 



Finally, among the various bodies which constitute the 

 internal substance of Diatomea3, we have to mention 

 some globules (globelli), more or less numerous, which 

 are found disposed either in transverse arches (archi), 

 round the median aperture of one lateral surface, but in 

 very few species. These Ehrenberg regarded as stomachs, 

 being led to that opinion by seeing them coloured with 

 indigo an effect, however, that could only be produced 

 by keeping the Diatomese a long time in water laden with 

 this colouring matter, and often renewed. Kiitzing be- 

 lieves this circumstance sufficient to show that they are not 

 to be deemed gastric sacs, but merely solid corpuscles, 

 which, being situate near an opening, exerted an especial 

 attraction upon the colouring matter. He makes no other 

 remark on their nature. 



