1^1 LI. 



Section 1: INTRODUCTION 



This introductory chapter traces the historical 

 development of the study of invertebrate tissue 

 respiration as a branch of experimental biology. 

 Interest in its study has appeared relatively 

 recently. It is only slightly more than 30 years 

 since the first work to come to the attention of 

 the authors appeared in print. Today tissue 

 respiration of the invertebrates is an established 

 domain of the experimental biologist. 



During the period 1929 through 1959, there 

 occurred at least 114 studies on the respiration 

 of invertebrate tissues as reported in 98 differ- 

 ent papers. Other published accounts, not known 



H 



I 



PHYLUM OR CLASS 



Fig. 1. Frequency distribution of studies on 

 invertebrate tissue respiration from 1929 

 through 1959 arranged according to phyla and 

 classes studied. A. Porifera: Demospongiae. 



B. Coelenterata: Hydrozoa, Scyphozoa, Anthozoa. 



C. Aschelminthes : Nematoda. D. Mollusca: 

 Gastropoda. E. Mollusca: Pelecypoda. F. Mol- 

 lusca: Cephalopoda. G. Annelida: Polychaeta. 



H. Annelida: Clitellata. I. Arthropoda: Merosto- 

 mata. J. Arthropoda: Crustacea. K. Arthropoda; 

 Insecta. L. Echinodermata: Holothuroidea. 



to us, may exist. Figure 1 shows the phylogene- 

 tic distribution of the animals used in these 

 studies. Note that, with the exception of the 

 Platyhelminthes, all the major invertebrate 

 phyla are represented. Investigators have used 

 insects and pelecypod mollusks most often, 

 cephalopod mollusks and crustaceans quite fre- 

 quently. The preponderance of insects as ex- 

 perimental animals seems particularly signifi- 

 cant when one examines figure 2. Here (fig. 2M) 

 the distribution of all studies on invertebrate 

 tissue respiration appears according to year. 

 Clearly apparent is a marked increase in the 

 total number of studies during the last decade. 

 It is also clear that one may attribute much of 

 this increase to work with insect tissues (fig. 

 2K). 



There are several other points worthy of note. 

 In the first place, the respiratory activity of 

 crustacean tissues (fig. 2 J) has been a regular 

 subject of investigation throughout the period of 

 1929 through 1959, with no single year or period 

 of years notable for any particularly large num- 

 ber of studies. Secondly, studies on Merostomata 

 (entirely confined to the American species or 

 horseshoe crab, Limulus polyphemus) appeared 

 for the most part during the 1930's (fig. 21). On 

 the other hand, work with tissues of cephalopod 

 mollusks has taken place largely during the late 

 1940's and 19 50's (fig. 2F). Some of this work 

 concerns the metabolism of squid giant axons, 

 now so important as a research tool to the neuro- 

 physiologist (see Keynes, 1958). 



The historical development of the types of 

 tissue preparations used in the study of tissue 

 respiration is the historical development of tis- 

 sue respiration itself. Earliest studies generally 

 concerned the respiration of whole organs or 

 pieces of organs. Warburg (1931) was the first 

 investigator to slice tissues into thin sections 

 in order to provide an adequate supply of oxygen 

 for cells of the interior. Because freehand slic- 

 ing produced non-uniform results, Deutsch (1936) 

 and later Stadie and Riggs (1944) devised mechan- 



