ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 813 



demonstrate the exchange of a nucleolar corpuscle between two 

 conjugating forms, and the reconstitution, after separation, of a new 

 nucleus and nucleolus from the products of this exchanged corpuscle. 

 There are seven principal stages, and each of the first six cor- 

 responds to the duration of a division of the primitive nucleolus, or 

 its products. The seventh, which is much longer than all the other 

 six, corresponds to the period of the reconstitution of the nucleus and 

 nucleolus, and terminates with their first fissiparous division. In 

 Euplotes patella the exchange of the nucleolar corpuscle is effected by 

 a special orifice which is provided with a vibratile apparatus. 



The nucleolus and its products, during division, pass through a 

 series of forms, of which five may be specially distinguished ; each 

 of these is characteristic of a stage in conjugation; the most im- 

 portant is that in which the nucleolus has a sj)herical form and is 

 granular; the fundamental substance of the nucleolus is converted 

 into a delicate filament, coiled on itself; it is in such a condition 

 that the nucleoli are exchanged. It is not correct to say that the 

 corpuscles are exchanged at the time when they are longitudinally 

 striated. As soon as the exchange is effected, separation of the con- 

 jugating cells commences. The stage of nucleolar reconstitution 

 commences thus ; the nucleus and nucleolus are represented by two 

 small corpuscles absolutely identical in size, form, and structure ; 

 that which is to form the nucleus grows rapidly, and soon becomes 

 conspicuous. All this time the separated forms are without a mouth, 

 take no food, and remain for the most part quite still. As the mouth 

 begins to be reconstituted the nucleus takes on the form and position 

 which is characteristic of the species ; the cells take in food greedily, 

 and after twenty- four to thirty hours of their new existence, during 

 which they have grown to almost twice their size, they divide by 

 fission. Sometimes the primitive nucleus breaks up and becomes 

 absorbed, but in Euplotes patella a pigment sometimes forms with the 

 new nucleus. In Paramecium bursaria it is completely retained, and 

 fuses with the fresh nucleus. 



Infusoria of the Gulf of Naples.* — Continuing the work of Prof. 

 Entz, Dr. E. v. Daday has noted the occurrence and given diagnoses of 

 some Infusorian forms hitherto unrecorded in the fauna of the Gulf of 

 Naples or elsewhere. His list is as follows: — 



Fam. Acineta Ehrbg. 1. A. levadiana Mereschk. 2. A. trina- 

 cria Gruber. 3. A. neapolitana n. sp. Fam. Enchelina St. 4. 

 Holophrya maxima n. sp. 5. Lagynus ocellatus n. sp. Fam. Trache- 

 lina St. 6. Amphileptus gigas Clap, and Lachm. Fam. Colepina 

 Ehrbg. 7. Coleps fusus Clap, and Lachm. Fam. Stentorina St. 8. 

 Stentor auricula S. Kent. Fam. Tintinnodea Clap, and Lachm. 9. 

 Codonella orthoceras Haeck. 10. C. punctata n. sp. 11. G. annulata 

 n. sp. 12. Dictyocysta ovalis n. sp. 13. D. mitra Hseck. 



Aerial Habits of Euglense-t — Dr. D. D. Cunningham states that 

 at almost any season many of the tanks in and around Calcutta are 



* MT. Zool. Stat. Neap., iii. (1886) pp. 481-98 (1 pi.). 



t Sci.-Gossip, 1886, pp. 163-4. From " The Relation of Cholera to Schizo- 

 myeete Organisms." 



