260 NATURAL HISTORY SOCIETY OF DUBLIN. 



Mr. Callwell then moved the following amendment, which was se- 

 conded by Mr. Lalor : — 



" That so much of the Keport of Council as relates to the invest- 

 ment of the Eeserve Fund of £74 13s. 6d. in the JSTew 3 per Cents, he 

 adopted ;" 



"Which, having been put from the Chair, was declared carried. 



The meeting then adjourned. 



FRIDAY EVENING, MAY 5, 1865. 



Eobert J. Montgomery, Esq., in the Chair. 



The Minutes of the preceding meeting were read and confirmed. 



Mr. "W". Archer read an extract from a letter addressed to him by 

 Dr. Gr. C. Wallich, E. L. S., on the subject of the value of Characters 

 in Protophyta, more especially in Desmidiacese. Mr. Archer ex- 

 plained that Dr. Wallich' s remarks therein were in reply to observations 

 of his own in a paper read before the Natural History Society of Dublin 

 on the 4th of December, 1863, entitled " Observations on Alicrasterias 

 Mahahuleshwarensis (Hobson), and on Docidium pristidm (Hobson);"* 

 and that Dr. Wallich, having done him the honour to write him a letter 

 containing a summary of his own views on the subject debated in the 

 paper referred to, had requested him to read the same to the Natural 

 History Society. The following is the extract : — 



" Pray do not for a moment think me inclined to take amiss any 

 differences of opinion on scientific matters. Every one has a right to 

 judge for himself; and in science, as in governments, truth can never 

 be arrived at on a large scale unless under the pressure of an opposition. 

 Besides, the question of specific limits is still in its infancy ; and those 

 who cling to permanent specific types are most fully justified in crying 

 out for the amplest proofs before relinquishing their ground. You know 

 of old that I am for no such permanence, but believe that I can trace at 

 every step more and more conclusive evidences that there exists a con- 

 stant tendency to modification by external influence. 



" The point at which you and I diverge is that at which we form 

 our estimates of the value of characters. You maintain that certain 

 characters, because they are more or less constant under the same con- 

 ditions — that is, in a given locality — afford evidence of persistence of 

 type. On the other hand, I hold they cannot be accepted as evidence 

 of this persistence unless they can be proved to occur under every va- 

 riety of conditions — that is, in widely remote localities. I speak from 



* "Proceedings of the Natural History Society of Dublin," vol. iv., Part 2, p. 79. 



