April 26, 1883 | 
NATURE 
603 
are so many unprofessional naturalists in all classes of 
the community and in all parts of the kingdom. Our 
dilettanti naturalists not only pursue their favourite study 
with a devotion and energy which Englishmen always 
exhibit in regard to a “hobby,’’ but they assist in all 
quarters in gaining for science true appreciation and 
popularity. Not merely so, but from their ranks many 
honoured leaders have sprung. It is chiefly for the ser- 
vice which he has rendered to this class of students that 
we consider Mr. Saville Kent is entitled to thanks, as was 
Andrew Pritchard and his editors in a past generation. 
In conclusion we may briefly epitomise the classifica- 
tion of the Infusoria followed by Mr. Kent. He regards 
the Infusoria as a legion or section of the Protozoa or 
unicellular animals characterised by having appendages 
which are zo¢ pseudopodia, lobose, or radiate (Rhizopoda), 
but are either flagelliform, cilia, or tentaculiform. The 
character of possessing a distinct mouth or mouths can- 
not be strictly applied to the whole group, since some 
few flagellate forms have not even a localised ingestive 
area, The classes and orders and families recognised in 
this legion are as follows :— 
Crass I.—FLAGELLATA. 
Order 1. TRYPANOSOMATA (Trypanosoma). 
Crder 2. RHIZOFLAGELLATA (Mastigamceba). 
Order 3. RADIOFLAGELLATA. 
Family 1. Actinomonadide ; 2. Euchitonide. 
Order 4. PANTOSTOMATA. 
Family 1. Monadide ; 2. Pletromonadide ; 3. Cerco- 
monadidz ; 4. Codoncecide ; 5. Dendromonadide; 6. 
Bikcecide ; 7. Amphimonadidz ; 8. Spongononadide ; 
g. Heteromitidz ; 10. Trepomonadide ; 11. Polytomide ; 
12. Pseudosporide ; 13. Spumellidz ; 14. Trimastigide ; 
15. Tetramitide ; 16. Hexamitide; 17. Lophomonadide ; 
18. Catallactidae, 
Order 5. CHOANOFLAGELLATA or DISCOSTOMATA. 
Section I. Gymnozoida. 
Family 1. Codonesigidee ; 2. Salpingcecidee ; 3. Phalan- 
steriidz. 
Section Il, Sarcocrypta (Lhe Sponges). 
Order 6. EUSTOMATA. 
Family 1. Paramonadide; 2. Astasiadz ; 3. Euglenide; 
4. Noctilucide ; 5. Chrysomonadide ; 6 Zygoselmide ; 
7. Chilomonadide; 8. Anisonemidz ; 9. Sphenomonadide. 
Order 7. CILIOFLAGELLATA. 
Family 1. Peridiniide ; 2 Heteromastigide ; 3. Mallo- 
monadide; 4. Stephanomonadide ; 5. Trichonemide. 
Cass II.—CILIATA. 
Crder 1. HOLOTRICHA. 
Family 1. Paramoecide ; 2. Prorodontide ; 3. Trache- 
lophyllidz ; 4. Colepide; 5. Euchelyide ; 6. Trachelo- 
cercidz; 7. Tracheliide ; 8. Ichthyophthiriide; 9. Ophryo- 
glenide ; 10. Pleuronemide ; 11. Lembide; 12. Tricho- 
nymphide ; 13. Opalinide. 
Order 2. HETEROTRICHA. 
Family 1. Bursariidz ; 2. Spirostomide ; 3. Stentoride ; 
4. Tintinnode ; 5. Trichodinopsidz ; 6. Codonellide ; 7. 
Calceolide. 
Order 3. PERITRICHA. 
Family 1. Torquatellide ; 3. Dictyocystide ; 3. Actino- 
bolide; 4. Halteriidz ; 5. Gyrocoridz ; 6. Urceolariide; 
7. Ophbryoscolecidz ; 8. Vorticellidz. 
Order 4. HYPOTRICHA. 
_Family 1. Litonotidz; 2. Chlamydodontide ; 3. Dyste- 
riidz ; 4. Peritromide ; 5. Oxytrichide ; 6. Euplotide. 
CLass III.—TENTACULIFERA, 
Order 1. SUCTORIA. 
Family 1. Rhynchetide; 2. Acinetide; 3. Dendro- 
cometidz; 4. Dendrosomidz. 
Order 2. ACTINARIA. 
Family 1. Ephelotide ; 2. Ophryodendride. 
The only feature in the above classification upon which 
it occurs to us to offer a remark is the limitation assigned 
to the class Flagellata. Putting aside the author’s spe- 
ciality as to the inclusion of the Sponges in that group, it 
seems that he has drawn up a very neat and, on the 
whole, satisfactory classification of the group. But on 
the one hand exception may be taken to the inclusion 
amongst the Flagellata of such forms as Mastigamoeba 
and Euchitonia, whilst, on the other hand, those who 
follow Stein will ask why such forms as Volvox and 
Chlamydomonas are excluded. Further we cannot 
accept as satisfactory the subordinate position assigned 
to Noctiluca, the proboscis of which is no ordinary fla- 
gellum, but of so special a character as to entitle its 
owner to a distinct order or even a class. The fact is 
that it is excessively difficult to say what monadiform or 
flagellate unicellular organisms should be associated with 
forms such as the Choanoflagellata and Eustomata which 
undoubtedly are rightly placed in one legion with the 
Ciliata, and what should be left among lower plants, or 
again in association with the pseudopodic Rhizopods. A 
flagellate condition in the early stages of development 
(a ‘‘monad form”) is common to a vast number of 
Protozoa and Thallophyta, and the mere flagellate cha- 
racter is not a sufficient basis for the construction of a 
natural group. Mr. Kent very properly proposes to sepa- 
rate as plants those flagellate forms which do not ingest 
solid particles of nutriment ; but he is no doubt aware of 
the difficulty of observation in this matter, and of the 
statement (probably an erroneous one) by Stein, that 
certain Volvocinee actually possess a cell-mouth and 
gullet. 
The true limitations of the natural group of the Flagel- 
late Infusoria will probably be ultimately found in the 
characters afforded by the series of events constituting 
the life-history of the various flagellate organisms which 
at first sight may appear to have a claim to be placed in 
that group. E. Ray LANKESTER 
OUR BOOK SHELF 
The Micrographic Dictionary. By J. W. Griffith, M.D., 
and A. Henfrey. Fourth Edition, Edited by J. W. 
Griffith, M D. (London; Van Voorst, 1883.) 
THE interval of eight years since the publication of the 
third edition of the “ Micrographic Dictionary” has been 
marked by substantial progress, not only in the micro- 
scope itself, but also in our knowledge of the structure of 
various classes of organisms included in the subjects 
specially treated. In the former of these two depart- 
ments the present edition may be regarded as fairly 
keeping pace with the advance of science; and the in- 
troduction forms a very useful treatise on the structure 
| and use of the microscope and of the various appliances 
