ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 969 



differentiated brancli of the Mastigopliora nor derived from any more 

 ancient lateral branch of the main trunk. Some branches of the Masti- 

 gophore-trnnk lead no doubt to new and very significant developments. 

 The Bacillaraceae form an isolated branch which may have had close 

 relations to the Dinoflagellata. The origin of the Sporozoa is involved 

 in great obscurity ; it is possible that they branched off from the main 

 trunk much earlier than is here represented, and somewhere near the 

 ChytridaceaB ; this remark applies only to the Gregarinida, as the 

 relations of the other so-called divisions of the Sporozoa to them are 

 still very doubtful. 



There can be no doubt as to the connection between the Protococ- 

 coidea and the Phytomastigoda, and it is almost certain that the higher 

 multicellular plants were derived from them. 



Prof. Biitschli doubts whether the Sponges have any relation to 

 the Choanoflag-ellata on the one hand, or the rest of the Metazoa on the 

 other. We have as yet no intermediate forms between the Metazoa and 

 the Mastigophora. He is inclined to accept with modifications Haeckel's 

 conception of a kingdom of Protista ; he extends it, indeed, for he 

 regards the morphological agreement of a unicellular nature as the 

 fundamental character ; but this does not prevent his seeing that in 

 practice the groups will fall into the kingdoms of Plants and Animals. 

 The divisions which in his work on Protozoa he treats of have no right 

 to be regarded as forming a natural group ; they are those which, on 

 account of their physiological characters, have been hitherto conven- 

 tionally regarded and" described as animals. They are the Sarcodina, 

 Mastigophora, Sporozoa, and Infusoria. 



Three further parts of the general treatise * have been issued, in 

 which, inter alia, the ciliation of the peristome and mouth, the endo- 

 plasm, the nutrient vacuoles and ingestion of nutriment, the contractile 

 vacuoles, the trichocysts, and the pigments of the Ciliata are discussed. 



Notes on Protozoa.! — Prof. A. Gruber communicates some de- 

 tached observations on Protozoa. 



(1) The encystation of Euglypha alveulata. — The small plates, ori- 

 ginally intended for a process of division, are utilized when encystation 

 sets in for the construction of the so-called internal shell. When the 

 encysted state is abandoned and the sheath bursts, the inner shell is 

 resolved into its component parts. In the subsequent division these are 

 utilized for their original purpose, and form the shell of the daughter- 

 Euglypha. 



(2) The division of Difflugia. — The point emphasized is the puzzling 

 way in which the Difflugia seems to take in as many particles as are 

 necessary for the formation of a new shell, and the fact that we seem 

 bound at this low level to speak of " an artistic impulse and of 

 instincts." 



(3) Nervous system of Infusorians. — In support of his conclusion that 

 the nervous functions of Infusorians are diffuse, Gruber describes the 

 interesting habit of a Stentor which he cut in longitudinal halves, and 

 which reunited with the ends of the halves reverse:!, but still remained 

 as good a unity as before. A similar experiment with a Volvox colony 

 is described. 



* Tom. cit., parts 47-99 (1888) pp. 1377-1488. Title-pages and tables of 

 contents for Abth. i. (Saroodina and Sporozoa), and Abth. ii. (Mastigophora) are 

 also published. f Ber. Nat. Gesell. Freiburg, ii. (1887) pp. 149-62 (1 pi.). 



