Mr, H. J. Carter on Fecundation in (Edogonium. 35 



therefore equally imjDrcgnative. It is much more common to 

 tind one cell smaller than the other in the conjugations oi Spi/o- 

 (jyra than to find them of equal size. I have also alluded to this 

 in the conjugations of the Uiatomese which have come under my 

 observation*, and am still inclined to think that this obtains 

 frequently among many of these organisms, not altogether " as 

 a mere accidental diversity and of no essential signification," as 

 Prof. "\V. Smith thinks f, but indicative of an approach to that 

 kind of impregnation in which the two bodies are unequal in size. 

 How the imin-egnated spore of (Edorjonium germinates, has 

 not yet, I think, been ascertained; that is to say, whether it 

 developes a single filament, like the spore of Spirogyra, or a 

 number of smaller spores, each of itself producing a new plant. 

 A priori, I should be inclined to infer the latter ; for the peculiar 

 lenticular form of the capsules with which the resting-spore is 

 filled, although they evince amylaceous contents under the action 

 of iodine, is so like that of the capsules of Euglena, and so unlike 

 that of the starch-grains of other Algse, as to indicate a nature 

 quite different from the latter. Moreover, some young plants of 

 a large species of CEdogonium possessing just after germination 

 a brown ring or collar round that ])oint which divides the bud 

 from the root, have frequently presented themselves to me in 

 company with an organism which at first would be taken for a 

 Thecamonadien, consisting of a lenticular, transparent capsule, 

 with a peculiar, brown, corrugated rim, enclosing a green diplo- 

 ciliatcd cell with eye-spot and contracting vesicle ; which pecu- 

 liar, brown, corrugated rim, being precisely like that embracing 

 the young plant of (Edogonium in company with it, has led mc 

 to the inference that this is in fact the spore of this (Edogonium. 

 The species to which this young plant of (Edogonium belongs, I 

 have not been able to ascertain ; but certainly there are many 

 plants of (Edogonium to be seen at this period without the ring, 

 and therefore it may be that these have come from unimpreg- 

 uated spores, such as those which I have before stated to be 

 formed from the contents of an ordinary cell, escaping by a rup- 

 ture at the joint (foot-note, p. 31). Does this rhig or collar, 

 then, afford a distinguishing mark of the young plant of (Edo- 

 gonium produced by impregnation ; and do the capsules con- 

 tained within the resting-spore pass into zoospores like that just 

 described before they germinate ? 



Abnormal Development. 

 There is a growth which frequently takes place from the 



'^- Annals, xvii. \i. \, 185G. 



t Syaopsis of British Diatomacese, vol. ii. Introduction, p. xiii. 



3* 



