ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 285 



we can only notice that the author finds that the phsBodellse are not of 

 protoplasmic nature, hut are excretory products which are retained 

 within the protoplasm in order to increase the size of the organism, 

 and so facilitate the respiratory interchange and the process of nutri- 

 tion. Special mention should be made of the numerous figures which 

 illustrate the paper. 



Foraminifera from the Lagoon at Funafuti.* — F. Chapman has 

 had a good opportunity of examining a foraminiferal lagoon fauna. The 

 prevailing genus is Amphistegina, whose specimens are smaller in the 

 middle of the lagoon than within reach of currents from without. The 

 spurred forms Calcarina and Tinoporus are both common near the rim, 

 but the latter rapidly disappears on travelling across the lagoon, and 

 Calcarina only is found in the samples from the lagoon-floor. In the 

 middle of the lagoon only three genera are present, Sagenina, Ampihi- 

 stegina, and Heterostegina. Perhaps the chief interest of the collection 

 is the evidence of environmentally produced variations or modifications. 



Trichocysts of Paramoecium aurelia.f — Prof. Jean Massart has 

 studied the discharge of the trichocysts in this Protozoon, and gives 

 the name of holism to the entire reflex action, from the application of 

 the stimulus to the completion of the reaction. The exciting agents 

 may be gentle pressure, an inductive shock, a rapid rise of temperature, 

 or chemical agents. In regard to chemical agents, however, there is 

 much variability, individuals of common descent reacting differently to 

 the same reagent. Typical reactions are shown in the following cases. 

 When the Infusorian is touched by picric acid, it instantly discharges 

 all its trichocysts. On the other hand, methylen-blue of ^i^ strength 

 produces a very slow and gradual discharge, and some reagents (elms- 

 oidine of -g-J-jj strength, picrate of ammonia of ^-Jq, iodine in potassium 

 iodide) produce death, slowly or rapidly, without any discharge. Thus 

 the production of the discharge does not depend upon the amount of 

 injury inflicted by the reagent. Further experiments showed that the 

 reflex occurs only at the stimulated points ; there is no transmission of 

 the stimulus. By very gradually raising the temperature, it is possible 

 to resolve the reflexes into their elements ; thus at one temperature 

 haptotaxism disappears while haptobolism persists, or chimiobolism 

 may persist intact while chimiotaxism persists only in part. 



Seasonal Dimorphism of Ceratium furca Duj.J — R. Minkiewicz 

 notes that there is a distinct difference in the anterior and posterior 

 processes in the summer and winter forms of this species. In summer 

 the processes are longer and the proportions are more " elegant." 



Monograph on Tentaculifera.§ — Rene Sand completes his elaborate 

 monograph on the Tentaculifera or Suctoria with an account of the 

 particular observations which he has made on 25 species of Trichophrya, 

 Ophryodendron, Urnula, Podophrya, Spliserophrya, Eallezia, Tokoplirya, 

 and Acineta. There is much that is interesting, but in reference to so 

 many different forms that a summary is beyond our scope. 



* Journ. Linn. Soc. (Zool.), xxviii. (1901) pp. 161-210 (2 pis.). 



t Bull. Acad. Roy. Belg. CI. Sci., 1901, pp. 91-106. 



% Zool. Anzeig., xxiii. (1900) pp. 545-6. 



§ Ann. Soc. Beige Micr., xxvi. 1899-1900 (1901) pp. 18-119, 8 ph. 



