532 



NATURE 



[April 6, 1893 



THE MORPHOLOGY OF BACTERIA. 

 Contribution d, VAtude de la Motphologie et du 

 D^veloppement des BactMachs. Par A. Billet, Doct. 

 en M^d., Mdddcin-Major de 2* classe. (Paris : Octave 

 Doin.) 



SINCE the publication of the "Peach-coloured 

 Bacterium," by Prof. Lankester, the subject of the 

 morphology of the bacteria cannot be said to have 

 received much attention from English investigators. 

 The department of bacteriology has to a great extent 

 been monopolised by the physician, who appears to 

 confine himself almost exclusively to the study of the 

 more practical bearings of the subject. It is therefore 

 refreshing to find a surgeon-major devoting his time to a 

 very thorough investigation of bacterial morphology. 



Dr. Billet's work dates back from 1885, and was 

 carried on for the most part in the Wimereux Laboratory 

 under the able direction of Prof. Giard. His communi- 

 cations were first published in the Bui. Sc. de la France et 

 de la Belgique, and the present work is a collected and 

 revised edition of these. The work consists of some 287 

 pages, and includes (i) an historical introduction, which, 

 owing to its succinctness and chronological sequence, will 

 be found of great use to the general bacteriologist ; (2) a 

 minute description of the life histories of Cladothrix 

 dichotoma and Bacterium parasiticum, and of two new 

 species named by Dr. Billet, Bacterium Balbiani and 

 Bacterium osteophilum ; (3) a very large bibliographical 

 index embracing some 662 references ; (4) a very beauti- 

 ful series of drawings. 



The author briefly sketches the progress of morphology 

 from the time of the doctrine of immutability of Cohn 

 and that of pleomorphism of Prof. Lankester, Cienkowski, 

 and Zopf. He shows how C. Robin (1847), in his 

 wonderfully interesting work, pointed to an affinity 

 between certain bacteria, his Lcptothrix baccalis, for 

 instance, and certain filamentous algae, the Leptothrix of 

 Kiitzing (1843) ; how, after the lapse of twenty-six years. 

 Prof. Lankester (1873 and 1876), determined, in his well- 

 known Bacterium rubescens, the coexistence of micro- 

 coccal, bacillary, and spirillar forms ; and finally, how 

 the theory of the " form phases" became further eluci- 

 dated by Cienkowski in 1887 in the " Morphologie 

 der Bakterien," and by Zopf in 1871 in his " Genetische 

 Zusammenhang von Spaltpilzformen." The latter observer 

 describes in the life history of the higher bacteria, coccal, 

 bacteroid, bacillary, vibrio, spirillar, leptothrix, and 

 zooglea forms ; the Clathrocystis roseo-persicina of Cohn 

 becomes the zooglea phase described in Bacterium 

 rubescens of Lankester, or more correctly, of the higher 

 Beggintoa rosea persicina. Starting with the above series 

 of form phases, the author ingeniously consolidates and 

 groups them into four stages, viz. : — i. Th&/ila7nentous^ 

 in which the bacteria are associated into larger 

 and shorter filaments. 2. The dissociated stage 

 in which the elements become free and motile, 

 and assume the well-known coccal bacteroid and other 

 forms. 3. The interlacing sidige — etat enchevetre'—vih&re. 

 the elements interlace with one another. 4. A zooglea 

 stage, in which the elements loose their movements and 

 aggregate themselves into certain definite forms. The 

 author goes on to show how definite and characteristic 

 NO. 1223, VOL. 47] 



are these groupings in the case of the organisms which he 

 has examined (see above). He points out that their 

 presence or absence depends upon surrounding conditions 

 — media, temperature, &c. But he further widens the 

 whole question in seeking to show that in the less highly 

 developed bacteria there are traces of the form phases 

 and form groupings of the more morphologically perfect 

 organisms. In this connection he briefly brings together 

 the observations which have been made upon the life 

 history of the lower bacteria. Thus the encapsulation 

 observed in the pneumococci, streptococci, tubercle, and 

 anthrax bacilli, sarcinae, &c., &c., may correspond to the 

 zooglea stage, for he recognises both pneumococcal, 

 merispomedia, and sarcina forms in his zooglea stage. 

 He regards the zooglea as protective, and forming when 

 the medium is becoming exhausted. We may add that 

 in the animal tissues encapsulation often appears depen- 

 dent upon the resistance offered by the tissues. He 

 further points out that the zooglea is often pigmented. 



In describing the life histories of his bacteria. Dr. 

 Billet makes some interesting remarks. Thus, he is in- 

 clined to believe that the cilium of the vibrio form is 

 nothing else than the residuum of the inner coat, and 

 that it is formed during the process of segmentation by 

 a drawing out and attenuation of the inner coat, like, for 

 example, when a glass rod is drawn out in a flame. As 

 many vibrios move about which have no cilia, he agrees 

 with Van Zieghem that the bacterial element has a proper 

 movement of its own, which is not dependent upon a 

 cilium, and he believes that the cilium of the Bacteria is 

 quite a different thing from the cilium of zoospores. He 

 carefully describes the movements of the vibrio forms, 

 and adds that they are greatly accentuated by a power- 

 ful light, a point first observed by Engelmann, in his 

 Bacterium photoinetricum. He also states that the passage 

 from the rectilinear forms to the less curve'd (vibrio) and 

 more curved (spirilla) forms, depends upon the degree 

 of temperature and amount of putrefaction ; the greater 

 the latter the more the twisted and appendiculate 

 forms. He concludes by giving the evidence in favour 

 of a relationship between the Bacteria and the Algae ; 

 the relationship appears great in the case of the or- 

 ganisms which he describes, but probably if he had 

 studied Actinomyces he might have similarly found very 

 many points in favour of a relationship with the mycelial 

 fungi. ' RUBERT BOYCE. 



OUR BOOK SHELF. 



Introductory Modern Geometry of Point, Ray ^ and Circle. 



By W. B. Smith. (London : Macmillan and Co., 



1893-) 

 This work of Prof. Smith's has a "very practical 

 purpose," viz. " to present in simple and intelligible 

 form a body of geometric doctrine, acquaintance with 

 which may fairly be demanded of candidates for the 

 Freshman class" of the Missouri State University. It 

 is shaped on the lines of such modern works as those by 

 Newcomb, Halsted, and Dupuis, to refer to English text- 

 books only ; but it most nearly resembles in some parts 

 the excellent little manual " on congruent figures," by 

 Prof. Henrici. " The work asks to be judged, at least in 

 its name, according to (the) spirit of modern geometry^ 

 and not according to the letter." 



