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Dr. J. B. Sanderson on the Attributes of [Nov. 22, 



other so much in volume and structure that they unquestionably 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 the Bacteria, not 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 which 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 distinctly 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 

 completely 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 iarior, and to the German word Gewebe, from which two 

 last the w T ords iu common use to designate the science of structure, viz. 

 histology and Gewebelelire, are made up. What I have asserted of the 

 germinal particles of Bacteria is, that no evidence exists of their being 

 endowed with that particular 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 ana- 

 tomical, 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 observation. As the obser- 

 vation is unaided or aided, the structure is said to be maeroscopical 

 or microscopical. The biologist cannot recognize ultra-microscopical 

 structure or organization except as matter of inference from observa- 

 tion, 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 



* Before I became aware that the contaminating particles of water are ultra-micro- 

 scopical I myself was engaged earnestly in hunting for germs both in water and air. 

 The search has been continued by others up to a much later period. Those who 

 desire information on the organized particles of the atmosphere will find the subject 

 exhaustively treated by Dr. Douglas Cunningham in a Report entitled " Microscopical 

 Examinations of Air," lately issued by H.M. Indian Government. 



