Marvels of the Universe 



77 



A Polycystin that might serve 

 as model for an artist's fishing 

 floal- 



A Polycyatin of spindle form. 

 the swollen portion pierced with 

 many six-sided openings. 



Jeffreys noticed them in the deep-sea 

 soundings of the North Atlantic. 



He further informs us that the siliceous 

 shells accumulated in thick deposits dur- 

 ing the last geological periods, and that 

 myriads of these exquisite microscopic 

 forms may be obtained from many strata 

 in Greece, Oran in Africa, and Bermuda. 

 He suggests that the Potycystins are best 

 examined as opaque objects, and, if minute 

 details are required to be seen, as trans- 

 parent bodies. 



Although the Poh'cystins are classed 

 under the Rhizopods, as stated, they 

 are, with some exceptions, looked upon 

 as fossil Radiolarians. Haeckel, to whom 

 the vast collections of micromarine life 

 dredged up during the Challenger e.xpedi- 

 tion were given for the purposes of classi- 

 fication, etc., was of this opinion, and he 

 divided the Polycystins into two groups, 

 those whose fundamental form was sphe- 

 rical and latticed and those whose form 

 was originally egg-shaped and perforated. 

 He pronounces those of the Barbados as 

 a deep-sea deposit, and that many of the 

 Polycystins are to-day extant and un- 

 changed in the ooze of the deep Pacific 

 Ocean, that the deep-sea mud of the 

 Central Pacific Ocean known as " Radio- 

 larian ooze," consists for the most part of 

 well-preserved shells of Polycystins. 



J. Miiller, another great naturalist, (in 

 1858) distinguishes the Polycystins as an 

 animal enclosed in a perforated flinty 

 shell. These shells are very minute and 

 of many forms. Spherical, conical, egg- 

 shaped and star-shaped kinds are common 

 and in most cases are flinty prolonga- 

 tions of the shell, which are symmetrical 

 and curved, or angular, or branched. 

 The perforations of the shell are large and 

 cause it to resemble a flinty network 

 rather than a test. The prolongations of 

 the flinty skeleton are not hollow, but 

 consist of transparent solid silica which is 

 developed during the digestive processes 

 of the animal. 



A quaint work on Nature, published 



A cylindrical Polycystin 



