182 . THE PHENOMENON OF 



without skinning.* I have also seen a skinning of the 

 cell by irregular tearing and exfoliation of the outer 

 lamellae of very much laminated cell-membranes, ex- 

 hibited very beautifully in Chroococcus decorticans,^ a 

 species very closely allied to Ch. rufescens (Nag. ' Einz. 

 Alg.,' t. i, A) and Ch. turgidus (Kiitz. ' tab. phyc.,' 6). 

 I have also met with irregular bursting and peeling off 

 of the outer coats of multicellular families, or sometimes 

 also of isolated cells surrounded by manifold coats, in a 

 Glaocapsa, with dark purplish-brown coats, standing 

 near to Gl. Magma (Kiitz. 'tab. phyc./ 22); also in 

 Glfsocystis vesiculosa, Nag., and GL ampla (Glceocapsa, 

 Kz.). Nageli also figures a skinning in Pleurococcus 

 miniatus (1. c., t. iv, E. 6). 



3. The slipping -out, or better, the expulsion from their 

 old membranes of rejuvenised cells, intimately trans- 

 formed, and passing into a renovated development, is dis- 

 tinguished from the skinning of the cells just examined, 

 in that the cell-membrane is not stripped off the resting 

 body of the cell, but, vice versa, the coat, remaining in 

 its place, drives out the contents separating from it, after 

 the latter have burst the envelope. This occurs parti- 

 cularly in the cases where the cell discharging its con- 

 tents is fixed, either by an independent attachment, or 

 belonging to tissue, by connection with its fellows. In 

 free cells no accurate limit can be drawn between 

 skinnning and slipping-out of the contents. Slipping-out 

 is the ordinary process by which the reproductive cells 

 of many Algae, Lichens, and Fungi, emerge from their 

 mother-cell chambers; if they are active, it is at the same 



* Vide plate ii, and the explanation. 



f The cells of this new species are smaller than in its two allies, from T 1 5 

 to 5)5 millim. in diameter, and verdigris green ; the colourless membranous 

 layers tougher, more clearly distinguishable. When the divisions of the 

 cell succeed rapidly, the thin coat exhibits but four layers; when the 

 division is intermitted, numerous (8 10) layers of membrane are found, 

 often appearing thickened on one side, and finally exfoliating irregularly. 

 Tincture of iodine colours the contents reddish or yellowish-brown, the 

 coats golden yellow. It occurs on the walls of the tufa caves near St. Aubin 

 on the Neunburger Sea. 



