H 



NATURE 



[Nov. 29, 1877 



them the centre of a large and admiring circle, and their 

 residence was one of the most favourite gathering-places 

 of the literary and scientific celebrities of Vienna. 



BACTERIA ^ 



IN a short paper communicated to the Royal Society at 

 the close of last session, Prof. Tyndall did me the honour 

 to criticise certain words reported to have been used by 

 me at a meeting of the Association of Medical Officers 

 of Health in January last. Although I am much indebted 

 to him for the opportunity he has thus afforded me of 

 discussing an important subject before this Society, I 

 cannot refrain from expressing my regret that he should 

 have thought it desirable to quote at length, and thus to 

 place on permanent record in the Society's Proceedings, 

 the expressions used on the occasion above mentioned. 

 I regret this because these expressions occur in an abbre- 

 viated and incomplete abstract of a hastily prepared 

 discourse not intended for publication. 



As, however, I am well aware that Prof. Tyndall's 

 purpose in his communication was not to criticise the 

 language, but the erroneous views which the language 

 appeared to him to contain, I shall make no further 

 reference to the quotation ; but shall regard it as the 

 purpose of the present paper, first to reply to the reason- 

 ing embodied in his last communication, and secondly 

 to corroborate certain statements previously made by me, 

 to which he has taken exception in the more extended 

 memoir published in the i66tlx volume of the Philosophical 

 Transactions. 



It will be my first object to enable the Fellows of the 

 Royal Society to judge how far the views I entertain 

 differ from those which have been enunciated here and 

 elsewhere by Prof. Tyndall. Biologists are much indebted 

 to him for the new and accurately observed facts with 

 which he has enlarged the basis of our knowledge, as well 

 as for the admirable methods of research with which he 

 has made us acquainted. As regards the general bearing 

 of these facts on the doctrine of Abiogenesis, I imagine 

 that we are entirely agreed. So far as I can make out, 

 the difference between us relates chiefly to two subjects, 

 namely, the sense in which I have employed the words 

 " germ " and " structure," and the extent of the knowledge 

 at present possessed by physiologists as to the structure 

 and attributes of the germinal particles of Bacteria. 



Although Dr. Tyndall, in the title of his paper, refers 

 to my "views of ferment," yet as he makes no further 

 allusion to them, I will content myself with stating that 

 in the passage quoted, the first sentence (from the words 

 " In defining" to the word "living") has nothing to do 

 with the following sentences, having been placed in the 

 position which it occupies in the quotation by the 

 abstractor. The paragraph ought to begin with the 

 words " Ten years ago." 



Of the meaning which attached itself to the word 

 " germ " in the days of Panspermism a correct idea may 

 be formed from the following passage from M. Pasteur's 

 well-known memoir " Sur les Corps organises qui existent 

 dans 1' Atmosphere." " There exist," says he, " in the air 

 a variable number of corpuscles, of which the form and 

 structure indicate that they are organised. Their dimen- 

 sions increase from extremely small diameters to one- 

 hundredth of a millim., i"5 hundredth of a millim., or even 

 more. Some are spherical, others ovoid. They have 

 more or less marked contours. Many are translucent, 

 but others are opaque, with granulations in'^their interior. 

 .... I do not think it possible to affirm of one of these 

 corpuscles that it is a spore, still less that it is the spore 

 of a particular species of microphyte, or of another, that 

 it is an egg or the egg of a particular microzoon. I 

 confine myself to the declaration that the corpuscles are 



• " Remarks on the Attiibutes of the Germinal Particles oi Bacteria, in 

 reply to Prof. Tyndall," by J. Burdon-Sanderson, M.D. , LL.P., F.R.S. 

 Paper read at the Royal Society, November 22, 



evidently organised ; that thejr reaemble in every respect 

 the germs of the lower organisms, and differ from each 

 other so much in volume and structure that they unques- 

 tionably belong to very numerous species." Such are the 

 "germs" of M. Pasteur, and such is the conception of a 

 germ which was entertained by informed persons up to 

 1870, and is very generally entertained up to the present 

 moment.' It is obvious that these " corpuscules organises " 

 were, if they had any relation to Bacteria, not bacterium 

 germs in Dr. Tyndall's sense, but "finished organisms," 

 and yet it was of these that M. Pasteur said that it was 

 "mathematically proved" that they were the originators 

 of the organisms v^^hich are developed in albuminous 

 liquids containing sugar, when exposed to the atmosphere. 



With reference to the word " structure " I would point 

 out that in the passage quoted from my lecture it is dis- 

 tinctly stated that the bacterial germ is endowed with 

 structure in the molecular sense, but not in the anatomical 

 sense. The meaning of the expression " anatomical 

 structure" was, naturally, not defined, considering that 

 the persons whom I was addressing might be supposed to 

 be familiar with it. As, however, my failing to do so has 

 apparently led to some uncertainty as to my meaning, I 

 must, to avoid future misunderstandings, define more com- 

 pletely the difference between the two senses in which the 

 word was used by me. 



The anatomical sense of the word structure may be 

 illustrated by referring to its synonyms, to the English 

 words texture and tissue, to the Greek word la-rlov, and to 

 the German word Gewcbe, from vv^hich two last the words 

 in common use to designate the science of structure, viz., 

 histology and Geivebelehre are made up. What I have 

 asserted of the germinal particles of Bacteria is, that no 

 evidence exists of their being endowed with that par- 

 ticular texture which forms the subject of the science of 

 histology. In biological language there is a close relation 

 between the words structure and organization, the one 

 being an anatomical, the other a physiological term ; 

 either of these words signifies that an object to which 

 it is applied consists of parts or structural elements, 

 each of which is, or may be, an object of obser- 

 vation. As the observation is unaided or aided, the 

 structure is said to be macroscopical for microscopical. 

 The biologist cannot recognise ultra-microscopical 

 structure or organisation except as matter of inference 

 from observation, i.e., from observing either that other 

 organisms, which there is reason to regard as similar to 

 the object in respect of which structure is inferred, actually 

 possess visible structure, or that the object can be seen to 

 possess structure at a later period of its existence. As 

 instances in which the existence of structure is inferred 

 the following may be mentioned : — The protoplasm of a 

 Rhizopod is admitted to have structure because, although 

 none can be seen in the protoplasm itself, the compli- 

 cated form of the calcareous shell which the proto- 

 plasm makes or models can be seen. By analogy 

 therefore other organisms which are allied to the Rhizo- 

 pod are inferred to have structure, and from these, or 

 from similar cases, the inference is extended to all kinds 

 of cells, with respect to which it is taught by physiologists 

 that although, in certain cases, no parts can be distin- 

 guished, the living material of which they consist is 

 nevertheless endowed with structure or organisation. 

 Similarly, we assume, that a Bacterium possesses a more 

 complicated structure than we can actually observe, 

 because in other organisms which are allied with it by 

 form and life history, such complications can be seen. 

 Again, in all embryonal organs we admit the existence of 

 structure before it can be seen, because in the course of 



1 Before I became aware that the contaminating particles of water are 

 ultra-microscopical I myself was engaged earnestly in huntmg for germs 

 both in water and air. The search ha-; been continued by others up to a 

 much later period. Those who desire information on the organised particles 

 of the atmosphere will find the subject exhau-tively treated by Dr. Douglas 

 Cunningham in a report entitled "Microscopical Examinations of Air," 

 lately issued by H.M. Indian Government. 



