December 24, 19 14] 



NATURE 



467 



behaviour, he tells me, is not in accord with anj 

 known form. He savs : • It is large, lo to 15 .« long, 

 nd shows a strong tendency in fluid cultures to 

 row into filaments, but 1 have not obser\ed any 

 branching." It is gram-positive, stains with ditti- 

 culty, and " its most characteristic feature is a brilliant 

 lemon yellow growth on auxietic agar." 



I should like to refer to one other recent experience. 

 In June 26-28, 1912. I prepared and sterilised six 

 tubes containing a vellow solution composed of 3 drops 

 of sodium silicate and S drops of liquor fern perne- 

 tratis to the ounce of water. Five of these tubes 

 were opened and their contents examined after periods 

 ranching from six to nine months, and in each embryo 

 Torulae and other torula-like bodies, together with 

 a few verv minute mvcelia of indeterminate types, 

 are recorded bv mv notes to have been found. The 

 sixth tube (No. 416) had been most of the time in 

 the incubator, and was not opened till August 2 of 

 this year— that is, more than two years after its pre- 

 paration. Some previous experiences induced me to 



Fig. 10. — X700. 



make such a trial. On opening the tube, in which 

 there was onlv a very small amount of deposit, 1 

 obtained the whole of it in two dips with a pipette 

 (the centrifuge used afterwards showed only a few 

 shreds, granules, and minute glass splinters). 1 he 

 contents of the dips revealed many of the same torula- 

 like bodies as had been found in the other tubes, 

 and also -four masses of minute mycelium issuing 

 from aggregates of minute spherical and ovoidal 

 eerms, together with granular matter, in part seem- 

 fnglv composed of typical cocci and short bacilli. 

 With the Moulds, as shown in Fig. 10, A and B, 

 there were masses of spherical spores with a central 

 dot in each, together with small heads of fructification 

 of Penicillium tvpe bearing similar acrospores. 



From a verv' similar solution contained in four 

 other tubes, prepared on May 17-19, 1912. in three, 

 which were opened at periods varying from seven to 

 ten months, the spores and mycelium of a mould of 

 Oospora tvpe were found bv mvself and others. Ihe 

 fourth tube was kept for nearly seventeen months 



NO. 2356, VOL. 94] 



I before it was opened, and two months before that 

 I date two obvious tufts of mould could be seen at 

 i the bottom of the tube, one of them nearly half an 

 ' inch in diameter. When this tube was opened in 

 Prof Hewlett's laboratorv, we saw that the growth 

 was again a mass of Oospora ' with the same charac- 

 teristic spores as had been previously found All this 

 set of tubes had been exposed to light during the 

 first six months, while the others had been in the 



incubator. 



Concluding Remarks. 



Manv critics of mv tube experiments have been 

 incredulous either as to the organisms found in the 

 tubes being reallv organisms, or else as to their b^ing 

 living and actuallv engendered withm them. Ihey 

 found it difficult to reconcile with ordinarily enter- 

 tained notions the idea that organisms like bacteria 

 and Torul^, to say nothing of Moulds, could be pro- 

 ducts of so-called "spontaneous generation." 



Let such critics spend two or three weeks only m 

 examining the developmental changes in the Zoogloeas 

 formed in a hav scum, and see how much many 

 other cherished preconceptions will be upset. Are 

 thev ever likelv to do it? Well, let them bear in 

 mind that three bacteriologists to whom I have 

 demonstrated these changes were unable to doubt 

 that the Fungus-germs, the Monads, and the Amoebae 

 were actuallv derived from the ultimate products of 

 segmentation ; and, further, that they were unable to 

 suggest 'infection" as an hypothesis that could 

 possiblv account for the many hundreds of similar 

 changes taking place simultaneously in each fragment 

 containing the different sets of Zoogloea. 



When they have seen similar results themselves, 

 what attitude can the critics take? If they see animal 

 products, such as Monads and Amoebae, taking origin 

 from aggregates of primordial vegetal units like 

 bacteria, and are compelled to recognise that such 

 Monads, altogether independently of any possible 

 inheritance, are enabled to throw out flagella, to 

 come into being provided with a nucleus, and to 

 develop activelv functioning contractile vacuoles, wi 1 

 thev still adhere to all their preconceptions, or will 

 thev rather admit their previous ignorance of nature s 

 potencv in this as well as in many other directions? 

 In a' recent able article^ on "Science and the Limits 

 of Belief," Sir Rav Lankester dwells ver>- forcibly 

 upon -the importance of knowledge based securely 

 on experimental demonstration and the examination 

 of actual things." As he says: "It is precisely by 

 the refusal to discuss possibilities, and by being at 

 the same time willing and anxious to receive and 

 verifv tangible demonstration of a fact, however im- 

 probable it mav appear," that all progress in science 

 has ever been made. With this I absolutely agree; 

 and can only trust that critics generally will adopt 

 a like opinion. 



\rchebiosis is a process that always takes place 

 beyond our ken, seeing that it must begin with mere 

 molecular collocations, gradually going on to the 

 formation of particles of an ultra-microscopic order. 

 And the onlv explanation that seems possible of the 

 growth of such particles into organisms like those 

 found in the tubes, as well as of the appearance of 

 the heterogenetic products that we have seen pro- 

 ceeding from Zooglceal segments, is to fall back upon 

 an exolanation which is generally admitted to account 

 for all the known forms of crystalline matter. Mole- 

 cular constitution, combined with the influence of the 

 environment, is what we have to appeal to there; and, 

 as Herbert Spencer over and over again insisted, the 

 forms and structures of organisms, under the influence 



•» As 'hown hv Fie- 4. in Nature for January 22, 1914- 

 5 In the R.P..A. Annual for 1915 (recently pnHis-hed 



