138 DU. PACKARD. 



quite the same arrangement as in the perichondrium which 

 comes in contact with it and in the tendon ; that is, they 

 are disposed in rows ; only the cells here are not bent and 

 not flat, but more or less cubical, consisting of a granular 

 protoplasm colouring readily in gold, and possessing a 

 roundish nucleus. Thus, in fig. 5 we see the fibrillar 

 matrix at a passing into the hyaline substance of the carti- 

 lage. Here we see also that the regular arrangement of the 

 cells disaj)pears ; those to be found on the transition line differ 

 from the ones at h, imbedded in the hyaline cartilage, and 

 from those at c in the fibrillar matrix, in no respect whatever 

 except that in the last case, where they are lying upon or 

 between fibrillar bundles, they are arranged in a chain-like 

 manner. 



In conclusion, I have to acknowledge my deepest obliga- 

 tions to my friend Dr. Klein, without whose assistance 

 during the investigation of the subject, in the preparation of 

 this article, and in the production of the figures that illus- 

 trate it, the present paper would have never appeared. 



The Embryology of Chrysopa, and its bearings on the 

 Classification of the Neuroptera. By A. S. Packard, 

 jun., M.D.1 



In a paper presented at the Burlington meeting of the 

 Association in 1867, I gave a brief sketch of the embryology 

 of Diplax, especially in the later stages. Those observations, 

 with the far more carefully elaborated studies of Brandt^ on 

 Calopteryx, another member of the family Libellulidse, have 

 made us acquainted with the embryology of the type of one 

 important division of Neuroptera, and now I have to off'er a 

 partial history of Chrysopa, the representative of another 

 important division of the group. I did not observe the forma- 

 tion of the blastoderm, but the blastodermic skin (" amnion ") 

 of Chrysopa, is of the same structure as in Calopteryx. At 

 the posterior end of the egg the round nucleated cells are 

 crowded together in the same way as in Calopteryx. The 

 primitive band is of the same general form, and floats in the 



' Trom the ' American Naturalist,' vol. v, Association Number, Sep- 

 tember, 1871. (Commuuicated, with corrections, by the Author.) 



* 'Beitriige zur Entwicklungsgeschichte der Libelluliden uud Hemipteren.' 

 St. Petersburg, 18G9. 



