106 SUMMARY OF CURRENT RESEARCHES RELATING TO 



form, very like Hsemogregarina stepanoivi of the tortoise, (6) a smaller, 

 mobile form, and (c) a club-shaped form with slight mobility. Two forms 

 were found much less frequently, and these seemed to be phases of (6, c). 



All these cellular parasites are minutely described as regards structure, 

 motion, effects, &c. The results of different reagents are also noted in 

 detail. The simultaneous occurrence of different forms in the same indi- 

 vidual, and the existence of several transition forms suggest a close rela- 

 tionship betwoen the different forms. Further, there is a close affinity 

 between the Hsematozoa lacertse and such Gregarinida as Hsemogregarina 

 testudinis. As to the history of the parasites, Danilewsky is not yet able 

 to supply definite information. His results have certainly shown the ex- 

 tensive distribution of such Gregarine forms, and are further of interest, as 

 he notes, in affording favourable opportunity for studying the modifications 

 of cellular life in response to peculiar environmental conditions. 



Parasitic Protozoa in Ciona intestinalis.* — The first part of the re- 

 sults of Prof. C. Parona's study of the j^arasites found in the intestine of 

 this Ascidian deals only with JJrospora Cionse. The author does not deal 

 with the organisms to be found on and within the branchial region, or 

 within the cloaca, nor with those numerous forms which settle upon the 

 test of Ascidians, but only with those which are found amongst the con- 

 tents of the intestine and stomach. These are studied by withdrawing the 

 contents by means of a pipette, and taking every precaution to obtain 

 the contents unmixed with any water from the exterior of the Tunicate. 

 The structure of the Gregarine, which belongs to Schneider's genus 

 Urospora, characterized by a set of caudal ai)j)endages, and is probably 

 identical with Frenzel's form Gregarina Cionse, is given, together with 

 certain observations on its development. 



The best method of preservation the author finds to be osmic acid 

 1 per cent, ; the object is then mounted in glycerin, which drives out the 

 osmic acid. The individuals are well preserved even at the end of three 

 months. 



BOTANY. 



A. CrENEBAL, including the Anatomy and Physiology 

 of the Phanerogamia. 



a. Anatomy, f 



(1) Cell-structure and Protoplasm. 



Destruction of the Molecular Structure of Protoplasm.| — Herr W. 

 Dctmer has experimented on the mode in which injurious external agencies 

 cause the death of the cell. For this purpose he found convenient objects 

 in succulent acid organs, such as the leaf and leaf-stalk of Begonia manicata. 



Chloroform kills the organ completely in about one hour. Coal-gas is 

 much more rapidly destructive than hydrogen, the leaves becoming com- 

 l^letely discoloured in the former gas in seven, in the latter in forty-eight 

 hours. Dilute hydrochloric acid or potash causes flaccidity in a very short 



* Journ. de Microgr., x. (188G) pp. 49G-501 (1 pi.). 



t Tills subdivision contains (1) Cull-structure and Trotoplasm; (2) Other Cell- 

 contents; (3) Secretions; (4) Structure of Tissues; and (5) Structure of Organs. 

 t Bot. Ztg., xliv. (188G) pp. 513-24. 



