Makela (1957) reports plant precipitins were 

 first demonstrated over 70 years ago against 

 mammalian sera. Boyd and Shapleigh (1954) 

 have shown that human soluble blood group 

 substances are specifically precipitated by 

 certain blood group specific plant extracts. 

 Bird (1961) through double diffusion precipitin 

 tests has demonstrated a specificity of 

 Ricinus communis and Abrus precatorius seed ex- 

 tracts for type XIV pneumococcus polysac- 

 charides. 



Using a microslide adaptation of the double 

 diffusion technique, we have tested a number 

 of plant extracts with a variety of fish sera. 

 Some of these extracts have precipitated com- 

 ponents of certain fish sera. So far, the most 

 promising of these extracts is from Rohinia 

 pseudoacacia bark. With this extract, a distinct 

 though quantitative variation has been found 

 in the reaction of Chinook salmon sera (fig. 2). 

 With this reagent, significant variations, inde- 

 pendent of sex, were found in sera of geo- 

 graphically separate populations of Chinook 

 salmon (table 10). Since all samples were 

 taken at the start of upstream migration after 

 the fish have ceased to feed, the variation also 

 appears to be independent of stage of maturity 

 and diet. 



DISCUSSION 



The above results indicate that phytoagglu- 

 tinins have a considerable potential value as 

 useful supplements to immune and normal sera 

 now employed in fish serology. From the point 

 of view of economy the use of phytoagglu- 

 tinins is desirable, for they eliminate the 

 disadvantages of maintaining animals. If a 

 useful plant extract is found, the investigator 

 has some assurance of an almost limitless 

 supply of uniformly specific reagent, providing 

 proper identification has been made and plant 

 components are availablelocallyor by request. 

 In the field, where refrigeration is impractical, 

 seeds and presumably dried barks are ideal 

 because extracts can be made whenever needed. 



Certain extracts appeared to possess either 

 species specificity or reactivity within a 



Figure 2. — Individual variation in chinook salmon sera 

 as demonstrated by Rohinia pseudoacacia bark ex- 

 tract. Positions 1 and 4 — Spring Creek (Columbia 

 River) sera; position 2--Anchor River; positions 3, 

 5. and 6--Stikine River. Observe strong reactions in 

 positions 1, 3, and 4, a weaker reaction in position 6, 

 a questionable reaction in position 2 and a negative 

 reaction in position 5. 



limited taxonomic range. The Cytisus scoparius 

 seed extract reacted exclusively with all 

 squawfish and squawfish hybrid cells tested. 

 The only reaction of the Laburnum vulgare bark 

 extract was with the single ratfish tested. The 

 peanut extract appeared to be specific for some 

 individuals of the somewhat closely related 

 corpaenids and cottids. The lack of reaction of 

 the soybean extract with more primitive 

 species may be indicative of a broad group 

 specificity of this reagent. Conversely, the 

 Sophora japonica bark extract reacted only with 

 certain more primitive species. The remainder 

 of the extracts tested exhibited no strong 

 group or species specific qualities. There are, 

 however, indications that testing a battery of 

 reagents at appropriate dilutions can give 

 species identification within groups. This con- 

 clusion, however, should be considered as 

 tentative because the samples were small in 

 most instances. 



The specificities detected by phytoagglu- 

 tinins appear to be much more sensitive to 

 changes caused by red blood cell aging than 

 those specificities detected by normal or im- 



14 



