252 Scientific Intelligence. 



mineral was described two years earlier under the name of 

 Kaliophilite, is overlooked. The appearance of the succeeding 

 parts of this great work will be looked for with interest, and it 

 cannot fail to receive the cordial reception which it deserves. 



6. Mazapilite. — The new mineral from Mazapil, Mexico, de- 

 scribed by Koenig (see this Journal, xxxvii), proves upon further 

 examination to be a calcium-iron arseniate near arseniosiderite. 

 An analysis gave : 



As 2 5 Sb 2 5 P. 2 5 Fe,0 3 CaO 11,0 

 43-60 0-25 014 30-53 14-82 9-83 = 9917. 



The mineral occurs in prismatic orthorhombic crystals, which are 

 black in color and only translucent and blood-red on the thinnest 

 edges; the specific gravity is 3-582. — Proc. Acad. Nat. Sci. 

 Philad., 45, 1888-9. 



III. Botany and Zoology. 



1. Ueber Entstehung und Wachsthum der Zetthaut ; En. Zach- 

 aeias (Pringsheim's Jahrb., xx, 2, p. 107). — The root-hairs of 

 Chara fcetida were used as materials, and the process of growth by 

 which the cell-wall is formed and grows, was followed out step by 

 step on living cells. The new formation begins with the appear- 

 ance of minute granules out of which minute rods are produced 

 which become wider and longer and finally unite to constitute a 

 coherent membrane. Between these rods one may see at first 

 some protrusions of protoplasm, but then later withdrawn. But 

 the origin and chemical relations of the granules which are seen 

 at the outset are as yet undetermined. Growth in thickness is 

 demonstrated to take place by the mechanical apposition of new 

 rods, and also by intercalation. Growth in superticies is believed 

 to be explained best by a combination of the two theories of iri- 

 tussceptiou and of apposition. G. l. g. 



2. l r olvox has been investigated afresh by L. Klein (Prings- 

 heim's Jahrb., xx, 2, p. 133).— The following are his conclusions: 

 I. Vblvox aureus and V. globator vary extremely with regard to 

 the size and number of the individual cells, the size and number 

 of the colonies produced, and the number of the oospores and bun- 

 dles of antherozoids. But, on the other hand, the size and shape 

 of the oospores of both are constant. 3. The protoplasts are en- 

 veloped by a thick gelatinous membrane which does not exhibit 

 a cellulose reaction. The inner space of the colonies is filled with 

 jelly, not with water. 11. Physiologically, a volvox-colony is to 

 be recognized as a community comparable to a colony of bees so 

 far as a division of labor is concerned. 13. The change in the dis- 

 tribution of sex coincides, as a rule, with the time of year. Thus, 

 in spring Vblvox aureus has predominately non-sexual colonies, 

 and those with pure dioecism ; in summer the antherozoids are 

 only in those colonies which are otherwise vegetative ; in late sum- 

 mer and autumn there are also the families which are monoeciously 

 protozynous. In general the sexual relations are more compli- 

 cated than was previously supposed. G. L. G. 



