\\>l. XIX. August, 1 910. A~ 



BIOLOGICAL BULLETIN 



M. \\r..\\ESE OF THE LAMELLIBRANCHS. 



H. C. BRADLEY. 



Dl I : "K PHYSIOUK.Y. L'SIVERSITY OF WISCONSIN. MADISON. \\ 1^ 



lii |N')2 ( iritliths pul)lishe(l an account of the finding of man- 

 gam -i- in i In- MIMM! of the lamellibranch, Pinna sqnanwsa. 1 

 far ,i~ I .mi aware this result has never been confirmed nor until 



nil\ ha- .111 examination of other molluscs led to an extension 

 of this isolated fact. To the student of comparative physiol 

 such a finding must be of considerable interest, adding one m<>iv 

 respiratoiA mechaiii-m to the list of five or six with which we 

 are familiar. At the same time it is highly improbable thai 

 I'inna squanwsa is the only mollusc utilizing manganese in a 

 respiratory compound; we should ex|>ect to find the element 

 in ni her forms more or less closely related to it. It is a matin 

 I i omiiion observation that the respiratory proteins of the more 

 hi.chK or-aiii/ed animals fall into a few general types, such as 

 ha-mo;Joliiii ,,r ha-mocyanin, and that while individual bloods 

 ma\ -ho\\ >u bile biological differences within one of these groups, 

 there i> ne\er an\ ilitliculty in determining chemically whether 

 a blood pigment is a ha-mocyanin, a haemoglobin, or some 

 oilier t\pical ((.niplex. The effective respiratory mechanisms 

 are thn- utiiie limited, so that we do not expect to find a single 

 member of a family possessed of a blood protein totally unlike 

 the other members of that family. 



For thi- iva-on we have extended the investigation of thi- 

 point Muucuhat with a view to determining what other lamelli- 

 braiuhs are pn.\i<led with a respiratory mechanism similar to 

 that of rinmi sqnanwsa. The most notable group which we 



/. rend, de I'Acad. dfs Set., CXIV.. p. 840. 

 161 



