Miscellaneous. 99 



with the Phyllopoda; and their embryonic development presents the 

 greatest analogy with that of the Scorpions and other Arachnida, 

 from which they cannot be separated. In the course of their em- 

 bryonic development we cannot distinguish any of the characteristic 

 phases of the development of the Crustacea ; and it is impossible to 

 distinguish in the course of this embryonic development either a 

 Nauplian or a Cyclopean phase. 



II. The analogy between the LimuU and the Trilobites, and the 

 affinity which connects together these two groups, cannot be doubted 

 for a moment by any one who has studied the embryonic develop- 

 ment of these animals. The laws of development are the same in 

 the Trilobites and the Xiphosura ; and the analogy between the 

 young Trilobites and the young LimuU is the greater in proportion 

 as we examine them at a less advanced period of their development. 

 On examining these young LimuU MM. Packard and Woodward were 

 struck with these analogies. 



III. The Trilobites, as well as the Eurypterida and the Pcecilopoda, 

 must be separated from the class Crustacea, and form, with the 

 Scorpionida and the other Arachnida, a distinct branch, the origin 

 of which has still to be ascertained. 



Note. — We do not yet positively know the characters of the legs 

 of Trilobites ; nevertheless, according to an important discovery made 

 last year in the United States, and published in the ' Quarterly 

 Journal of the Geological Society of London,' Mr. Billings thinks he 

 has demonstrated that the Trilobites had articulated legs like those 

 of the LimuU. The question of the form and characters of these ap- 

 pendages, hoAvever, is a secondary question from the morphological 

 point of view. The form varies with the functions of the organs in 

 the same natural group. The NebaUce, with their foliaceous feet, 

 are true Decapods; and the Cladocera are not Phyllopods, but Ento- 

 mostraca which, from the morphological point of view, must be 

 placed beside the Copepoda. Even if the Trilobites were completely 

 destitute of appendages, we could not conclude from this that they 

 do not belong to the same group as the Pcecilopoda. — Comptes 

 Rendus de la Soe. Entom. Belg. October 14, 1871 (N^o. 67), p. 10. 



Cells in Crystalline Form. By Hermann Kaksten. 



That the vegetable cell may appear in an actual crystalline form 

 was discovered by Karsten in 1847 in the milky juice of a Euphor- 

 biaceous plant (Jutroplia curcas), and made known by him at one 

 of the meetings of the Society of Friends of Natural History in 

 Berlin. It was only in the year 1859 that the discoverer referred 

 to the subject in more detail in PoggendorfF's 'Annalen ;' and aU 

 those who conceive the first origin of plants in primaeval time as a 

 process of crystallization, having for its basis an organic primitive 

 material, must have had particular satisfaction in the knowledge of 

 this fact. It is, in fact, sufficiently striking. For generations past 

 chemistry has accustomed us to the phenomenon of products of 

 organic activity, so-called organic compounds, especially the highly 



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