QUARTERLY CHRONICLE. 169 



described, drawn, and their meaning discussed by Dr. 

 Leydig. 



Societa Italiana di Scienze Natarali. " Studies on Cochineal 

 Insects,'"' by A. Targioni Tozzetti. — Professor Tozzetti has 

 been good enough to send us this and the following memoir, 

 which are very exhaustive and valuable treatises. The com- 

 plete history and anatomy of several Cocci is most elaborately 

 worked out by the author, and illustrated by most faithful- 

 looking drawings in seven large quarto plates. So 

 thoroughly complete and careful examination as Professor 

 Tozzetti has given to these insects makes his work a most 

 important pendant to the researches of Huxley, Lubbock, 

 Balbiani, Mecznikow, and Claparede, on allied hemipterous 

 forms. 



" On the Light-organ of Luciola Italica, and on the Muscular 

 Fibre of Arthropods," by Targioni Tozzetti. This paper 

 contains a full and careful description of the organs in 

 question, illustrated by two plates. 



Miscellaneous. — "A Monograph on the Structure and De- 

 velopment of the Shoulder -Girdle and Breast-Bone in the 

 Vertebrata,'' by W. Kitchen Parker, F.R.S. (Ray Society.) 

 — " We cannot," says Mr. Parker, " take a step in this de- 

 partment of anatomical science without a thorough acquaint- 

 ance, not only with the histology of the skeleton, but also 

 with that of the rest of the tissues that go to make a verte- 

 brate animal." Hence the last volume issued by the Ray 

 Society has considerable interest for microscopical observers. 

 The study of osteology is just now receiving from the hands 

 of such men as Professors Gegenbaur and Huxley and Mr. 

 Parker a turn in quite a new direction, the importance of 

 which cannot be overestimated. Following in the steps of 

 Rathke, the osteologist has now to consider in his determina- 

 tions of homologous bones, not merely the position or rela- 

 tions of the bone in question to other bones, but, above all, 

 he has to ascertain and make allowance for its origin and 

 mode of development. " Skin-bones," " membrane-bones," 

 and " cartilage-bones," are now carefully discriminated. 

 Mr. Parker, taking counsel, as he says, with Professor 

 Huxley, proposes three terms — endostosis, ectostosis, and 

 parostosis — by which to distinguish the three chief modes of 

 ossification. " Endostosis " is that ossification which com- 

 mences in the intercellular substance of hyaline cartilage. 

 That bony matter which is first found in the almost structure- 

 less inner layer of the perichondrium, in immediate contact 

 with the outermost cartilage-cells, is formed by a process 

 which may be called " ectostosis." Such a bony formation 



