ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 403 



functions. Of the mode and place of formation of the fatty oils, the 

 aleurone, the crystalloids, and the crystals, very little is at present 

 definitely known ; and the object of the present investigation is to de- 

 termine some points in connection with this subject. The following are 

 the more important results attained. 



Crystals of calcium oxalate which occur within the cell are formed 

 exclusively in the vacuoles ; and this theory is not opposed to the fact 

 that they are carried along in the currents of protoplasm. Kosanoff's 

 cellulose sacs are formed by the death of the cell and subsequent passive 

 distension by turgidity. The envelopes of cellulose or protoplasm are 

 deposited on the crystals after their formation. 



Aleurone-grains are vacuoles filled up by albuminoids. The albumen 

 dissolved in the vacuole becomes solid by the drying of the ripening 

 seed; in the softening of the seed, on the other band, which precedes 

 germination, the reverse takes place. During the formation of the seeds, 

 the originally single vacuole of each cell divides, as its contents are 

 being formed, into a very large number of small vacuoles ; and the 

 reverse of this takes place again during germination ; after germination 

 the empty cells again contain a single central vacuole. The albumen 

 dissolved in the vacuoles of ripening and germinating seeds can be pre- 

 cipitated by several reagents, such as dilute nitric acid, absolute alcohol, 

 saline solutions, &c. By means of these substances the slow disappear- 

 ance of the albumen on germination in the dark can be followed step by 

 step. Globoids are formed in the vacuoles. 



Crystalloids may be formed in the most various parts of the cell, 

 viz. : — in the vacuole (in seeds, in Thallophytes, and in Pothos scandens) j 

 in the protoplasm (in the potato) ; and in nuclei and plastids. 



The fatty oils are always formed in the protoplasm, and in two 

 different ways, viz. in specially prepared spots, elaioplasts (as in species 

 of Vanilla, Hepaticse, Vaucheria, and possibly Laurencia and its allies) ; 

 or distributed uniformly through the protoplasm (as in seeds). 



The protoplasm can become perforated during plasmolysis without 

 being thereby killed. 



Connection of the Direction of Hygroscopic Tensions with the 

 Structure of the Cell-wall.* — Herr C. Steinbrinck has investigated the 

 causes of the hygre)SCopic tensions which result in the twistings of 

 organs, such as the involucral scales of Compositee, the legumes of 

 Leguminossa, and the awns of Erodium, Pelargonium, Stipa, and Avena, 

 which are connected V7ith their dissemination. He attributes the pheno- 

 menon to two causes : — the production and the direction of striae and of 

 pores on the organ in question ; and the difference in the capacity for 

 swelling of different cell-walls and layers of cell-walls. 



C2) other Cell-contents (including' Secretions). 



Spectrum - analysis of the Colours of Flowers.j— Dr. N. J. C. 

 Miiller has examined the spectroscopic reactions of the pigments of sixty- 

 five different plants, which he classifies under three heads, viz. : — red 

 (erythrophyll), yellow and orange (xanthophyll), and blue to violet and 

 purple (anthocyan). The following varieties are enumerated, and 

 the characteristics of the spectra given, together with the reaction 



* Ber. Deutsfh. Bot. Gesell., vi. (1888) pp. 385-98 (1 pi.). 



t Jahrb. f. Wiss. Bot. (Pringsheim), xx. (1889) pp. 78-105 (2 pis.). 



