804 SUMMARY OF CURRENT RESEARCHES RELATING TO 



long tail, of striated muscular structure, larger than the flagella, and 

 sometimes even double ; its form is somewhat variable, and it is des- 

 titute of the ridge and serrated crest which is seen in Trichomonas. 



In this same intestine was found a remarkable organism, Giardia 

 agilis, which the author thinks ought to occupy an intermediate place 

 between " certain Schizomycetes, such as Vibrio, Spirillum, and the 

 Monads." The body is formed of two clearly distinct portions : the 

 upper and larger one has large vacuoles ; the lower is much narrower, 

 thicker, almost filiform, and resembling the large body of a Vibrio ; 

 but its length is much greater, and it terminates in a fine point. 

 Between these two regions there is a slight constriction. From the 

 lower circumference of the former portion long flagella proceed in a 

 downward direction, which often remain attached to the narrow 

 portion for varying distances ; two other flagella are inserted at the 

 inferior free extremity. The narrow portion is very mobile and very 

 flexible ; it constitutes a locomotive organ of very great power, and 

 consequently the organism moves with remarkable activity. This 

 kind of tail has an undulatory movement, similar to that of the tail 

 of a tadpole, but at the same time it has a movement of "circum- 

 duction," and the combination of these two movements gives to it a 

 helicoidal motion of remarkable vivacity. 



Intestinal Parasites of Oysters.* — A. Certes has found, in the 

 oyster, Hescamita inflata, which is also found in the brackish waters 

 of the region he studied ; in addition to forms which presented two 

 posterior filaments there were some observed that had four, and these 

 are regarded as individuals undergoing longitudinal fission. The 

 most interesting parasite was a new species of Trypanosoma — T. 

 balbianii, which has at first sight the appearance of a large Spirillum. 

 The action of the vapour of osmic acid, or iodized serum, and methyl- 

 blue reveals the presence of a membrane, which is not rigid, but which 

 appears to be contractile, and to obey the will of the animal ; no 

 mouth, anus, or contractile vacuole were to be detected in the interior, 

 nor is there any nucleus or nucleolus ; so that it is a Moneron with 

 an undulating membrane. 



BOTANY. 



A. GENERAL, including Embryology and Histology of the 

 Phaner o gamia. 



Structure and Movement of Protoplasm.|— G. Klebs gives a 

 useful summary of the present state of our knowledge respecting the 

 structure of protoplasm and the movements to which it is subject, and 

 the connection between these two. He sums up by saying that, while 

 we are still ignorant of the chemical composition of protoplasm, and of 

 the mechanical forces which lie at the base of its mobility, it becomes 



* Comptes Kendus, xcv. (1882) pp. 463-5. 

 f Biol. Centralbl., i. (1881) pp. 577-94. 



