80 NATURAL SCIENCE [August 
they describe the minute structure of the calcareous plates or 
coccoliths and rhabdoliths, and record the existence in the cocco- 
spheres of a single central green chromatophore, separating into two 
on the division of the cell. They regard Coccosphaeraceae as a group 
of Unicellular Algae, and they define the group with the limits of its 
genera and species. The coccospheres and rhabdospheres from the 
surface are compared with those of the deep-sea deposits and their 
identity established. They are also compared with geological 
coccoliths and rhabdoliths from various beds, and many objects re- 
garded by geologists as true coccoliths and rhabdoliths are rejected. 
A large number of new Peridiniaceae were discovered and are 
formally described and figured. No specific diagnoses of marine 
Peridiniaceae have previously been published, authors of species 
having depended on figures, and, at most, a few words of description. 
No doubt the present systematic treatment of the subject will 
conduce to greater order in the group. The authors record the 
occurrence of all the forms in seven tabular statements, one for each 
collecting voyage. 
A study was also made of the species of Pyrocystis, of which 
a new one is described. The facts here recorded tend, in the 
opinion of the authors, to confirm the view originally expressed by 
Sir John Murray, its describer, that it is an unicellular alga, 
though doubts had been entertained of the accuracy of this opinion 
by several biologists. 
THE MISSOURI GARDEN 
THE ninth annual report of the Missouri Botanical Garden, issued by 
the director, Professor Trelease, has just reached us. As in the case 
of previous issues, it contains the garden reports, embellished with 
photographic reproductions of features of interest, and a number of 
scientific papers, several of which deal with those dry-loving tropical 
plants for the growth of which the garden is eminently suited. One 
of these papers, a revision of the genus Capsicwm (which includes the 
Chili and Cayenne peppers), with special reference to garden varieties, 
by H. C. Irish, studies an interesting example of the assumption of 
numerous forms by plants which have been long cultivated. The 
genus, which is an ally of Solanwm, the potato and tomato genus, 
evidently originated in the tropics of America, whence it was 
probably first brought to Europe by Columbus, and is now widely 
spread in the Old World tropics. Linnaeus made four species, and 
the number of specific names has since so increased as to reach 
at the present time nearly one hundred, of which the Index 
Kewensis recognises over fifty as good. Asa Gray, however, 
suggested that these might perhaps all be reduced to two, and Dr 
Sturtevant, who made a special study of the genus, collecting and 
